掺硼（B）非晶硅（a—Si：H）材料固相晶化（SPC）的研究

对掺硼（Ｂ）材料的固相晶化进行了研究。通过对不同掺Ｂ浓度的ａ－Ｓｉ：Ｈ样品退火前后的Ｘ射线衍射，光吸收系数、电导率、激活能及Ｈａｌｌ迁移率的测量发现，Ｂ原子在固相晶化过程中起晶核作用，晶化后的样品具有较高的迁移率及电导率，同时具有较大的禁带宽度。当掺Ｂ浓度仅为０．１７％时，晶化后样品的电导率４．３５ｓｃｍ＾－１，迁移率为１４０ｃｍ＾２Ｖ＾－１Ｓ＾－１，禁带宽度Ｅ０４＝２．１６ｅＶ。该材料是一种较好     

EBV法制备Znln2S4薄膜的性质研究

用电子束加热真空蒸发法（ＥＢＶ法）制备了厚度为３５０ｎｍ的ＺｎＩｎ２Ｓ４薄膜。研究了最佳成膜工艺条件和最新电子能谱分析结果；通过不同气氛处理可以控制材料的导电类型，典型膜的电阻率为２．５×１０＾－１Ω．ｃｍ，Ｈａｌｌ迁移率为５２ｃｍ＾２．Ｖ＾－１．ｓ＾－１，载流子浓度为１．４２×１０＾１７ｃｍ＾－３，禁带宽度为２．１３ｅＶ。探讨了ＺｎＩｎ２Ｓ４膜的导电机理，并制作了ＺｎＩｎ２Ｓ４－Ｓｉ太阳电池。     

P型μC－SiC：H窗口材料掺杂特性的研究

用等离子体射频辉光放电法，在低衬底温度（＜１７０℃）、小ｒｆ功率（＜６０ｍＷｃｍ２）条件下，实现了硼掺杂硅碳合金薄膜材料的微晶化。获得了暗电导率σＤ～０．２ｓｃｍ－１、光带隙宽度Ｅｏｐｔ～２．２ｅＶ的ｐ型微晶氢化硅碳合金（μＣ－Ｓｉ：Ｂ：Ｈ）薄膜。晶化的关键是Ｈ２稀释率和掺杂水平的控制。对该材料的掺杂效应、光电特性以及掺杂水平对材料结构的影响进行了详细研究。     

SnO_2／p接触特性对a－Si太阳电池填充因子的影响

用ＰＥＣＶＤ方法制备出高电导率（～０．２ｓｃｍ－１）、宽带隙（～２．２ｅＶ）的Ｐ型微晶化硅碳合金（ｐ－μｃ－ＳｉＣ：Ｈ）薄膜材料。利用ｐ－μＣ－ＳｉＣ：Ｈ／ｐ－ａ－Ｓｉ：Ｈ复合结构做ａ－Ｓｉ太阳电池的窗口材料，明显改善了ＳｎＯ２／ｐ之间的接触特性，从而使１０ｃｍ×１０ｃｍ单结集成型电池的填充因子从０．７０以下提高到０．７２。     

RTCVD工艺制备poly—Si薄膜太阳电池的研究

报道了快速热化学气相沉积（ＲＴＣＶＤ）工艺制备多晶硅（ｐｏｌｙ－Ｓｉ）薄膜及电池的实验和结果。采用ＳｉＨ２Ｃｌ２作为原料气体，衬底温度为１０３０℃时，薄膜的生长速率为１０ｎｍ／ｓ。发现薄膜的平均晶粒度及载流子迁移率与衬底温度和材料有关。用该薄膜在未抛光重掺杂磷的硅衬底上制备１ｃｍ２的ｐ＋ｎ结样品电池，无减反射涂层，其转换效率为４．５４％（ＡＭ１．５，１００ｍＷ／ｃｍ２，２５℃）。     

优质氧化锌透明导电膜

报道了采用反应电子束蒸发技术制备优质氧化锌透明导电膜的工艺和结果。典型的结果：电阻率低达２×１０－４Ω．ｃｍ，霍尔电子迁移率为５２ｃｍ２（Ｖｓ）－１，厚４０００×１０－１０ｍ膜的方块电阻为８．９Ω／□，可见光透过率大于９０％。分析了源掺杂、镀膜气氛、衬底温度等参数与膜的电导和透光特性的关系。     

激光开槽埋槽电极硅太阳电池的性能及分析

报道了面积为４５ｃｍ＾２的激光开槽、埋槽电极硅太阳电池的研制情况。在ＡＭ１．５、２５℃、１００ｍＷｃｍ＾－２的条件下，测试３６片该类太阳电池，其输出参数的平均值为：Ｊｓｃ＝３６．１ｍＡｃｍ＾－２，Ｖｏｃ＝６３３ｍＶ，Ｆ．Ｆ＝０．７９８，η＝１８．２３％，最后，分析了该类电池特有的工艺及结构设计的作用机理。     

快速汽相沉积法制备硅薄膜太阳电池

对在重掺杂抛光单晶硅衬底上用ＲＴＣＶＤ法形成硅薄膜太阳电池进行了研究。衬底为〈１００〉晶向ｐ＋ ＋ 型重掺硅片,电阻率为５×１０－ ３Ωｃｍ 。主要工艺过程为：在衬底上生长一层硅薄膜同时掺硼,膜厚３８μｍ ,扩磷制备ｐ－ｎ 结,背面蒸Ａｌ及Ｔｉ／Ｐｄ／Ａｇ 制背电极,正表面在扩散后生长一层ＳｉＯ２ ,前面用光刻剥离法制备Ｔｉ／Ｐｄ／Ａｇ 电极,制成的１ｃｍ ２ 太阳电池,开路电压ＶＯＣ＝ ６１２．８ｍ Ｖ,短路电流ＩＳＣ＝ ２９．３ｍ Ａ,填充因子ＦＦ＝ ０．７５７９,效率η＝ １３．６１。对一些影响电池特性的因素进行了研究,发现硅薄膜的掺杂浓度、发射层的掺杂浓度以及减反射层都对太阳电池的特性有较大影响。     

硼离子掺杂类金刚石薄膜及C（B）n—Si异质结光伏特性

采用直流弧光放电等离子ＰＣＶＤ法，沉积获得硼掺杂类金刚石薄膜，该材料ｐ型半导体，电阻率５－１０Ωｃｍ。俄歇电子能谱测试表明，硼离子含量为０．８％，由扫描电镜和激光喇曼谱分析可知，薄膜以非晶为主，观察到许多线径为０．５－１．０μｍ的金刚石结晶微粒。     

CdS／CdTe－CdS／Cu_2S异质二重结薄膜太阳电池的设计与计算

根据半导体材料的性能参数，考虑光电压Ｖ和耗尽区宽度Ｗ的变化对光电流ＪＬ的影响，较严格地计算了ＣｄＳ／ＣｄＴｅ和ＣｄＳ／Ｃｕ２Ｓ两种异质结单晶薄膜太阳电池的光伏特性曲线。然后在的条件下，对由上述两种异质结构成的二重结太阳电池的ＣｄＴｅ、Ｃｕ２Ｓ厚度进行匹配，计算各种组合下二重结太阳电池的光伏特性曲线。理论证明最佳匹配厚度Ｈｍａｘ约为９．０６μｍ，最大短路电流、开路电压、转换效率分别为１４．２２ｍＡｃｍ－２、１．３Ｖ和１４、６８％。     

Preparation of highly conductive p-type μc-Si:H window layer using lower concentration of hydrogen in the rf glow discharge plasma

Boron doped p-type hydrogenated microcrystalline silicon (μc-Si:H) films have been prepared by radio-frequency glow discharge method. Highly conductive p-type μc-Si:H films can be obtained even with lower concentration of hydrogen in the rf glow discharge plasma if chamber pressure is low. Effects of increase in hydrogen (H₂) flow rate and chamber pressure have been studied. The structural properties of the films have been studied by X-ray diffractometry. The electrical and optical characterization have been done by dark conductivity, Hall measurements and optical absorption measurements respectively. Film with conductivity 0.1(Ω-cm)⁻¹ with band gap 2.1 eV has been obtained.     

Preparation of highly conductive p-type μc-Si:H window layer using lower concentration of hydrogen in the rf glow discharge plasma

Boron doped p-type hydrogenated microcrystalline silicon (μc-Si:H) films have been prepared by radio-frequency glow discharge method. Highly conductive p-type μc-Si:H films can be obtained even with lower concentration of hydrogen in the rf glow discharge plasma if chamber pressure is low. Effects of increase in hydrogen (H₂) flow rate and chamber pressure have been studied. The structural properties of the films have been studied by X-ray diffractometry. The electrical and optical characterization have been done by dark conductivity, Hall measurements and optical absorption measurements respectively. Film with conductivity 0.1(Ω-cm)⁻¹ with band gap 2.1 eV has been obtained.     

Study of the solid phase crystallization behavior of amorphous sputtered silicon by X-ray diffraction and electrical measurements

In situ X-ray diffraction (XRD) measurements have been used to study the amorphous-to-crystalline transformation in hydrogenated amorphous silicon (a-Si:H) thin films deposited by DC-Magnetron Sputtering at 300°C. The a-Si:H layers of 2.85 μm thickness were solid phase crystallized (SPC) and the crystallization kinetic was studied from in situ XRD measurements and also by in situ electrical conductance measurements during isothermal annealing at 630°C. The apparition and the evolution of the (1 1 1) peak in the XRD spectra during the annealing of the layer permit to follow the SPC kinetic which is the same as the electrical conductance kinetic (G=f(t)) performed in the same annealing conditions as in the XRD experiment. Several isothermal annealings at different temperatures permit to extract the characteristic parameters of the crystallization from the G=f(t) evolutions. These parameters are the thermally activated crystallization characteristic time and its activation energy.     

Wide optical band gap window layers for solar cells

In this paper, the preparation of amorphous silicon carbide with very wide optical band gap and high conductivity were reported. The films were fabricated under the “silane–plasma starving” and H₂ dilution condition in conventional capacitively coupled reactors. The silane–plasma starving condition and H₂ dilution play important roles in decreasing H content, modulating the material toward the ordered structure and enhancing the doping ratio. This is an easy way to prepare wide optical band gap and highly conductive p-type window layers for a-Si : H-based solar cells.     

Boron doped amorphous diamond window layer deposited by filtered arc for amorphous silicon alloy p-i-n solar cells

In order to improve the conversion efficiency of amorphous silicon (a-Si:H) alloy p-i-n solar cells, the original p-a-Si:H window layer is substituted by the boron-doped amorphous diamond (a-D:B) films deposited using filtered cathodic vacuum arc technology. The microstructural, optical and electrical properties as functions of the boron concentrations in the films were, respectively, evaluated by an X-ray photoemission spectroscopy, an ultraviolet-visible spectrometer and a semiconductor parameter analyzer. The photovoltaic parameters of the solar cell modules were also detected as functions of boron concentration. It has been shown that the conductive a-D:B films could be obtained and still remained a wide optical gap. The p-i-n structural amorphous silicon solar cell using the a-D:B window layer increased the conversion efficiency by a roughly 10% relative improvement compared to the conventional amorphous silicon solar cell because of the enhancement of short wavelength response.     

掺杂对FeS2薄膜光电性能的影响

采用磁控溅射淀积合金膜和纯铁膜,通过离子注入掺杂,研究了不同条件下FeS2薄膜的晶体结构,光吸收系数、电阻率、载流子浓度等光电性能,并用正电子湮灭谱研究了膜内的空位缺陷。结果表明,掺杂提高了薄膜的导电性能。离子注入使薄膜光吸收系数增加,禁带宽度上升,霍尔迁移率提高;合金溅射导致光吸收系数降低,禁带宽度下降,载流子浓度升高。注入Zn2 退火前空位浓度较大,退火后空位浓度低于纯FeS2膜。     

Oxygen modified diamond-like carbon as window layer for amorphous silicon solar cells

In the present study, the effect of in situ layer-by-layer oxygen plasma treatment (OPT) on optical, nano-mechanical and electrical properties of layer-by-layer diamond-like carbon (DLC) thin films was explored. In situ layer-by-layer OPT on layer-by-layer DLC films led to drastic variation of optical band gap from 1.25 eV to 2.6 eV and hardness from 16.1 GPa to 25.3 GPa. Wide band gap and the band gap feasibility over wide range may lead to its realization as p-type window layer in p–i–n solar cells and variable band gap layers in tandem solar cells. Simulations of a-Si:H based p–i–n solar cells was also carried out by considering OPT–DLC films as p-type window layers that yielded maximum efficiency of 8.9%. In addition, due to high hardness and other excellent nano-mechanical properties, these OPT–DLC films can be treated as hard, protective and encapsulate layers on solar cells particularly in n–i–p configuration. It is important to mention that OPT–DLC film as p-layer can minimize the use of additional hard, protective and encapsulate layer.     

Low-temperature growth of thick intrinsic and ultrathin phosphorous or boron-doped microcrystalline silicon films: Optimum crystalline fractions for solar cell applications

The growth kinetics and optoelectronic properties of intrinsic and doped microcrystalline silicon (μc-Si:H) films deposited at low temperature have been studied combining in situ and ex situ techniques. High deposition rates and preferential crystallographic orientation for undoped films are obtained at high pressure. X-ray and Raman measurements indicate that for fixed plasma conditions the size of the crystallites decreases with the deposition temperature. Kinetic ellipsometry measurements performed during the growth of p-(μc-Si:H) on transparent conducting oxide substrates display a remarkable stability of zinc oxide, while tin oxide is reduced at 200°C but stable at 150°C. In situ ellipsometry, conductivity and Kelvin probe measurements show that there is an optimum crystalline fraction for both phosphorous- and boron-doped layers. Moreover, the incorporation of p-(μc-Si:H) layers produced at 150°C in μc-Si:H solar cells shows that the higher the crystalline fraction of the p-layer the better the performance of the solar cell. On the contrary, the optimum crystalline fraction of the p-layer is around 30% when hydrogenated amorphous silicon (a-Si:H) is used as the intrinsic layer of p–i–n solar cells. This is supported by in situ Kelvin probe measurements which show a saturation in the contact potential of the doped layers just above the percolation threshold. In situ Kelvin probe measurements also reveal that the screening length in μc-Si:H is much higher than in a-Si:H, in good agreement with the good collection of microcrystalline solar cells     

Evolution of the properties of CuAlSe2 thin films with the oxygen content

CuAlSe₂ thin films have been synthesized by annealing, under argon flow, a multilayer structure of thin Cu, Al and Se layers sequentially deposited by evaporation under vacuum. It is shown that the oxygen content depends not only on the evaporation content but also on the argon flow. The properties of the thin films are modified by this oxygen percentage: when no more than 4–5 at % of oxygen is present in the films, their optical properties are very similar to that of single crystals. The inter-band transitions A, B, C typical of such chalcopyrite structure are clearly visible on the absorption spectra. The variation of the conductivity of these films in the high temperature domain is as that expected in CuAlSe₂, while in the low temperature, grain boundaries are dominant.     

Optoelectronic properties of doped layers for a-Si solar cells prepared using helium dilution

This paper is the first part of a work about the preparation and characterisation of doped layers for hydrogenated-amorphous-silicon (a-Si:H) thin film solar cells. An approach for RF-glow discharge deposition of a-Si consisting of dilution of silane (SiH₄) in helium and application of high RF-power densities, has been tested. In this first part the optimisation of n-type layers has been accomplished. The influence of preparation conditions on the optical and electrical properties of the films has systematically been studied. It has been found that the use of high RF-power densities and high dilution levels of SiH4 in He favour the doping efficiency and film quality when the substrate temperature is 300°C. As a result of these investigations, n-type layers with thicknesses between 250 and 360Å, an optical gap about 1.95 eV, a dark-conductivity of 0.1 (Ωcm)⁻¹ and an extended-state conductivity activation energy of 0.1 eV have been prepared. Such properties make them suitable for their use as n-type layers for a-Si:H thin-film solar cells.