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1.
R.F. sputter deposition of Sb doped CdTe thin films was carried out with targets containing different amounts of antimony (CT: 0, 2.5, 10 and 20 at.%). The substrates were kept at different temperatures (Ts) of 200, 275, 350 and 450 °C. Three different argon pressure values: 2.5, 5 and 15 mTorr were used. The lowest dark resistivity (ρ) at room temperature (RT) was 9.0 × 105 Ω cm, which is one of the lowest values reported in the literature for Sb doped CdTe. Highly transparent (∼90%) and conductive (ρ = 3.7 × 10−4 Ω cm) F doped CdO (n-type) thin films, prepared at room temperature by the sol-gel method, were employed as window and top-contact. The configuration of the fabricated solar cell was (Au-Cu)/p-CdTe/n-CdO/glass. Open-circuit voltage (Voc) and short-circuit current density (Jsc) at room temperature have the highest values for high Ts, low Pg and CT = 10 at.%. Despite the fact that Voc and Jsc are lower than those reported in the literature, we think this work is useful as a basis for the search of more competitive CdTe/CdO based PV devices.  相似文献   

2.
The phosphorus-doped amorphous carbon (n-C:P) films were grown by r.f. power-assisted plasma-enhanced chemical vapor deposition at room temperature using solid phosphorus target. The influence of phosphorus doping on material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, the solar cell properties such as series resistance, short circuit current density (Jsc), open circuit current voltage (Voc), fill factor (FF) and conversion efficiency (η) along with the spectral response are reported for the fabricated carbon based n-C:P/p-Si heterojunction solar cell were measured by standard measurement technique. The cells performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm2, 25 °C). The maximum of Voc and Jsc for the cells are observed to be approximately 236 V and 7.34 mA/cm2, respectively for the n-C:P/p-Si cell grown at lower r.f. power of 100 W. The highest η and FF were found to be approximately 0.84% and 49%, respectively. We have observed the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.  相似文献   

3.
For a remarkable improvement of conversion efficiencies of single-crystalline silicon (c-Si) solar cells, we have been investigating rear surface structures. The structure has a highly conductive boron (B) doped hydrogenated microcrystalline silicon (μc-Si:H) film with a wide optical bandgap between a p-type c-Si substrate and a rear contact instead of a heavily diffused layer. The conditions of depositing the μc-Si:H film were investigated. Both short-circuit current density (Jsc) and open-circuit voltage (Voc) of the cell with the μc-Si:H film are much higher than those without the film. The Voc obtained was higher than 650 mV and the efficiency was 19.6% for a 5 cm × 5 cm cell. It is confirmed that a low-high heterojunction of the c-Si substrate and the μc-Si:H film is very effective in preventing minority carriers near the rear contact from recombining.  相似文献   

4.
A ZnO-covered TiO2 (denoted as ZnO/TiO2) film was prepared by incorporating a small quantity of particulate ZnO in a TiO2 matrix by thermal chemical vapor deposition. When used in a dye-sensitized solar cell, an enhancement was observed in both short-circuit photocurrent (Jsc) and open-circuit voltage (Voc) by 12% and 17%, respectively, relative to those of a cell containing a bare TiO2 film. The observed Jsc enhancement is attributed to the increase in the surface area of the ZnO/TiO2 film, and the Voc enhancement to the formation of a potential barrier by ZnO at TiO2/electrolyte interface. The films were characterized by FE-SEM, EDX, and XRD.  相似文献   

5.
The heterostructure n-CdO/a-C/p-Si is proposed for use as a solar cell device. The heterostructure consists of two semiconductor layers having different optical band gaps. An ultrathin layer of a-C with a narrow optical band gap is located between these layers. The photovoltaic effect in this device has been investigated. It is shown that the short-circuit current Isc=46 mA/cm2 for heterostructure n-CdO/a-C/p-Si corresponds to the values obtained in the best solar cells based on crystalline silicon. It is also shown that the heterostructure n-CdO/p-Si (without a-C) has a short circuit current which is much weaker.  相似文献   

6.
This paper reports on the successful deposition of boron doped p-type (p-C:B) and phosphorus doped n-type (n-C:P) semiconducting carbon films and fabrication of p-C:B on n-type silicon (Si) substrate (p-C:B/n-Si) and n-C:P/p-Si cells by pulsed laser deposition at room temperature using graphite target. The B and P powder were respectively mixed with graphite powder in range from 1% to 20% of B by weight in the targets (Bwt.%) and 1–10% of P by weight in the targets (Pwt.%), and compressed into pellet targets. The B and P atoms incorporated in the films were determined by X-ray photoelectron spectroscopy to be in the range of 0.2–1.75 and 0.22–1.77 atomic percentages, respectively. The cells performances have been given under illumination IV rectifying curve (AM 1.5, 100 mW/cm2, 25 °C). The open circuit voltage (Voc) and short circuit current density (Jsc) for p-C:B/n-Si are observed to vary from 230 to 250 mV and 1.5 to 2.2 mA/cm2, respectively. While, for n-C:P/p-Si cells the Voc and Jsc are observed to vary from 215 to 265 mV and 7.5 to 10.5 mA/cm2, respectively. The p-C:B/n-Si cells fabricated using 3 Bwt.% shows highest energy conversion efficiency, η = 0.20% and fill factor, FF = 45%. While, the n-C:P/p-Si cell fabricated using 7 Pwt.% shows highest of η = 1.14% and fill factor, FF = 41%. The quantum efficiency of p-C:B/n-Si and n-C:P/p-Si cells are observed to improve with percentage of B and P, respectively. The contribution of quantum efficiency in the lower wavelength region (below 750 nm) may be due to the photon absorption by carbon layer and in the higher wavelength region is due to the Si substrates.  相似文献   

7.
CIGS films were treated in In–S aqueous solution for high-efficiency CIGS solar cells. The In–S aqueous solution contained InCl3 and CH3CSNH2 (thioacetamide). The In–S treatment modified the CIGS surface favorably for high-efficiency CIGS solar cells as evidenced by the increase in Voc, Jsc and FF. The In–S treatment formed thin CuInS2 layer on the CIGS surface which contributes to the high efficiency and stable performance of the CIGS solar cell. The best cell showed an efficiency of 17.6% (Voc=0.649 V, Jsc=36.1 mA/cm2 and FF=75.1%) without any annealing and light soaking before IV measurement.  相似文献   

8.
GaSb quantum dot (QD) solar cell structures were grown by molecular beam epitaxy on GaAs substrates. We investigate the reduction in open-circuit voltage and study the influence of the location of QD layers and their delta doping within the solar cell. Devices with 5 layers of delta-doped QDs placed in the intrinsic, n- and p-regions of a GaAs solar cell are experimentally investigated, and the deduced values of Jsc, Voc, fill factor, efficiency (η) are compared. A trade-off is needed to minimize the Voc degradation while maximizing the short circuit current density (Jsc) enhancement due to sub-bandgap absorption. The voltage recovery is attributed to the removal of the QDs from the high-field region which reduces SRH recombination. The devices with p- or n-doped QDs placed in the flat band potential (p- or n-region) show a recovery in Jsc and Voc compared to devices with delta-doped QDs placed in the depletion region. However, there is less photocurrent arising from the absorption of sub-band gap photons. Furthermore, the long wavelength photoresponse of the n-doped QDs placed in the n-region shows a slight improvement compared to the control cell. The approach of placing QDs in the n-region of the solar cell instead of the depletion region is a possible route towards increasing the conversion efficiency of QD solar cells.  相似文献   

9.
Abhik Kumar Das 《Solar Energy》2011,85(9):1906-1909
The J-V equation of a solar cell is implicit and requires iterative calculation to determine the fill factor and the maximum power point. Here an explicit model for J-V characteristic is proposed which is applicable to a large variety of solar cell. This model allows an easy estimation of fill factor from four simple measurements of the bias points corresponding to Voc, Jsc, and any two voltage values lying between 0 and Voc, where Voc is the open circuit voltage and Jsc is the short circuit current density.  相似文献   

10.
The transparent electric windows based on dye-sensitized nanocrystalline TiO2 solar cells have been prepared. The solar cell consists of dye-sensitized TiO2 electrode with a TiO2 layer of an about 8 μm thickness and of a 80×80 mm2 active area, Pt counter electrode and redox electrolyte. The solar cell shows a transmittance of approximately 60% in the visible range and an open-circuit voltage (Voc) of 0.64 V and a short-circuit photocurrent (Jsc) of 250 mA. A moderately transparent electric window composed of nine unit solar cells in series generates Voc of 5.7 V and Jsc of 220 mA at one sun light intensity.  相似文献   

11.
A synthetic route was developed to link N3 dye to polyacrylic acid (PAA) using ethylenediamine (en) as the linker. The resulting complex, PAA–en–N3, was then coated onto a TiO2 film. The modified TiO2 film electrode (hereafter PAA–en–N3/TiO2), when used as the photoanode in a dye-sensitized solar cell (DSSC), exhibited enhanced solar energy conversion efficiency compared with that of the usual DSSC with the N3/TiO2 film electrode. The increase in efficiency was attributed to the increased open-circuit voltage (Voc) and short-circuit photocurrent (Jsc). The increase in Voc was attributed to the formation of a hydrophobic PAA–en–N3 layer on the TiO2/electrolyte interface, while the increase in Jsc was attributed to the additional dye acquired by the TiO2 film from the PAA–en–N3 complex.  相似文献   

12.
Thickness reduction of CdTe absorption layer down to 1 μm has been achieved by controlling the temperature profile used during the close-spaced sublimation (CSS) growth. Transparent conducting oxides, such as indium tin oxide (ITO) and textured fluorine doped tin oxide (SnO2:F) films have been investigated as transparent electrodes for such 1-μm-thick CdTe absorption layers to increase the incident light confinement and thus to achieve higher conversion efficiency. The contribution in solar cell performance has been found in the case of textured TCOs with optimum haze ratio (roughness). Conversion efficiencies of 10.6% (Voc: 0.75 V, Jsc: 22.02 mA/cm2, FF: 0.64, area: 1 cm2) and 11.2% (Voc: 0.78 V, Jsc: 22.6 mA/cm2, FF: 0.63) have been achieved for only 0.6-μm-thick CdTe absorption layers with SnO2:F-TCO of 11% and 3% of haze ratios, respectively.  相似文献   

13.
We report on boron-doped μc-Si:H films prepared by hot-wire chemical vapor deposition (HWCVD) using silane as a source gas and trimethylboron (TMB) as a dopant gas and their incorporation into all-HW amorphous silicon solar cells. The dark conductivity of these films was in the range of 1–10 (Ω cm)−1. The open circuit voltage Voc of the solar cells was found to decrease from 840 mV at low hydrogen dilution H-dil=91% to 770 mV at high H-dil =97% during p-layer deposition which can be attributed to the increased crystallinity at higher H-dil and to subsequent band edge discontinuity between μc-Si:H p- and amorphous i-layer. The short circuit current density Jsc and the fill factor FF show an optimum at an intermediate H-dil and decrease for the highest H-dil. To improve the conversion efficiency and the reproducibility of the solar cells, an amorphous-like seed layer was incorporated between TCO and the bulk p-layer. The results obtained until now for amorphous solar cells with and without the seed layer are presented. The I–V parameters for the best p–i–n solar cell obtained so far are Jsc=13.95 mA/cm2, Voc=834 mV, FF=65% and η=7.6%, where the p-layers were prepared with 2% TMB. High open circuit voltages up to 847 mV could be achieved at higher TMB concentrations.  相似文献   

14.
This article reports for the first time in the literature, a dye sensitized solar cells with 1.21% efficiency (Voc=0.56 V, Jsc=6.70 mA/cm2 and F.F.=0.33) on paper substrates. The current dye sensitized solar cell technology is based on fluorine doped SnO2 (FTO) coated glass substrates. The problem with the glass substrate is its rigidity and heavy weight. Making DSSCs on paper opens the door for both photovoltaic and paper industries. The potential of using mature paper making and coating technologies will greatly reduce the current PV cost. Paper substrate based DSSCs not only offer the advantages of flexibility, portability and lightweight but also provide the opportunities for easy implantation to textile. In this study, a low temperature process is developed to coat uniform nickel on paper substrate as the metal contact to replace the traditional expensive FTO. The Ni paper showed excellent conductivity of 8-10 Ω/□. It is found that the control of metal oxide electrode morphology is critical to solar cell performance. The TiO2 film has the tendency to crack on Ni coated paper, which resulted in the shunt of the device and no solar cell efficiency was obtained. ZnO film on the other hand had good morphology tolerance on Ni coated paper and yielded solar cell efficiency of 1.21% (Voc=0.56 V, Jsc=6.70 mA/cm2 and F.F.=0.33) under AM 1.5 (activation area is 0.16 cm2). The control sample of ZnO solar cell on FTO glasses has the efficiency of 2.66% (Voc=0.64 V, Jsc=9.97 mA/cm2 and F.F.=0.42).  相似文献   

15.
We have studied the influence of electrolytes on the photovoltaic performance of mercurochrome-sensitized nanocrystalline TiO2 solar cells using LiI, LiBr, and tetraalkylammonium iodides as the electrolyte. Short-circuit photocurrent density (Jsc) and open-circuit photovoltage (Voc) depended strongly on the electrolyte. Jsc of 3.42 mA cm−2 and Voc of 0.52 V were obtained for the LiI electrolyte and Jsc of 2.10 mA cm−2 and Voc of 0.86 V were obtained for the Pr4NI electrolyte. This difference in photovoltaic performance was due to the change in the conduction band level of the TiO2 electrode. Large Voc of 0.99 V was obtained for the LiBr electrolyte due to the large energy gap between the conduction band level of TiO2 and the Br/Br2 redox potential. Solar cell performance also depended strongly on organic solvent, suggesting that the physical properties of solvents such as Li ion conductivity and donor number affect photovoltaic performance.  相似文献   

16.
Poly-Si films were produced using a metal-induced growth technique by sputtering from an n-type Si target onto a 50 nm thick Co seed-layer at 625°C. Silicon grew heteroepitaxially on the CoSi2 layer formed due to the reaction between the sputtered Si atoms and Co at the beginning stage of deposition. A 5 μm thick Si film with grain features up to 1 μm was produced on the thin and flexible tungsten substrate by using a two-step sputtering method. The films also have a natural texture structure on the surface that is strongly recommended in thin-film solar cells in order to obtain high current density by increasing incident light trapping. After post-sputtering annealing at 700°C, the measured minority carrier lifetime for poly-Si film was 1.33 μs which shows the film to be suitable for photovoltaic applications. To explore the photovoltaic applications by using MIG poly-Si films, Au/n-Si Schottky photodiodes were fabricated due to the process simplicity. The effects of different parameters, which include film doping density, active-layer thickness, Si film surface conditions and hydrogenation, were studied. It was found that with the increasing of doping density, the open-circuit voltage (Voc) increased while short-circuit current density (Jsc) decreased. Increasing the poly-Si active-layer thickness tended to improve the light absorption with an increased Jsc, but the Voc was decreased due to a higher value of reverse saturation current. Because the metal/semiconductor interface condition facilitates the carrier transport in Schottky devices, the earlier study of modifying the Si surface by polishing showed an improved Voc. The overall photo response was further improved by plasma hydrogenation.  相似文献   

17.
CuIn1−xGaxSe2 (CIGS) thin films were formed from an electrodeposited CuInSe2 (CIS) precursor by thermal processing in vacuum in which the film stoichiometry was adjusted by adding In, Ga and Se. The structure, composition, morphology and opto-electronic properties of the as-deposited and selenized CIS precursors were characterized by various techniques. A 9.8% CIGS based thin film solar cell was developed using the electrodeposited and processed film. The cell structure consisted of Mo/CIGS/CdS/ZnO/MgF2. The cell parameters such as Jsc, Voc, FF and η were determined from I–V characterization of the cell.  相似文献   

18.
Effect of ZnO nanorod surface on fabricating the perovskite solar cell and its performance were studied. Varied thickness of ZnO nanorod arrays with rough surface condition were achieved through the control of hydrothermal growth time and acid treatment. Samples based on modified ZnO nanorod arrays exhibit an impressive increase on the open‐circuit voltage (Voc) and fill factor (FF) compared with the untreated ones. Further research onto the surface topography and electrochemical impedance spectroscopy test indicates that the improvement should be attributed to the suppression of the charge recombination rate at the ZnO nanorod/CH3NH3PbI3 interface. In order to enhance the short‐circuit current density (Jsc) performance one step further, Cl‐doped perovskite crystal was introduced into the cell. Because of its longer electron diffusion length, an impressive Jsc is received. The final combination of the two methods with the optimized thickness of the ZnO nanorod brought a total power conversion efficiency of 13.3% together with Voc~0.92 V, Jsc~23.1 mA/cm2, and FF~63%. This work highlights the importance of the surface morphology of the electron transport layer and its interface contact with the light absorbing layer in a solar cell structure. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

19.
The phosphorus-doped amorphous carbon (n-C:P) films were grown by radiofrequency (RF) power-assisted plasma-enhanced chemical vapor deposition (PECVD) at room temperature using a solid phosphorus target. The influence of phosphorus doping on the material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, solar cell properties such as series resistance, short-circuit current density, open-circuit current voltage, fill factor and conversion efficiency along with the spectral response are reported for the fabricated carbon-based n-C:P/p-Si heterojunction solar cells by standard measurement technique. The cells’ performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm2, 25 °C). The maximum open-circuit voltage (Voc) and short-circuit current density (Jsc) for the cells are observed to be approximately 236 V and 7.34 mA/cm2, respectively, for the n-C:P/p-Si cell grown at a lower RF power of 100 W. The highest energy conversion efficiency (η) and fill factor (FF) were found to be approximately 0.84% and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.  相似文献   

20.
In this paper, the photovoltaic feature of metal-boron carbide-silicon (MCS) solar cell was reported. The boron-doped diamond-like carbon thin film on n-silicon substrate has been prepared using arc-discharge plasma chemical vapor deposition (PCVD) technique. The conductivity and the resistivity of the film were measured by Bio-Rad Hall5500PC system to be p-type semiconductor and 3–12 Ω cm/□, respectively. The boron content in the films was about 0.8–1.2%, obtained from Auger electron spectroscopy (AES), and some microcrystalline diamond grains (0.5–1.0 μm) embedded in the mainly amorphous network were revealed through scanning electron microscope (SEM) and Raman spectrum. The performance of Au/C(B)/n-Si heterojunction solar cells has been given under dark IV rectifying curve and IV working curve (with 100 mW cm−2 illumination). A measurement of open-circuit voltage Voc=580 mV and short-circuit current density Jsc=32.5 mA cm−2 was obtained. Accordingly, the energy conversion efficiency of the device was tentatively determined to be about 7.9% in AM 1.5, 100 mW/cm2 illuminated.  相似文献   

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