共查询到20条相似文献,搜索用时 46 毫秒
1.
《Ceramics International》2021,47(24):34473-34480
We fabricated high-quality n-type Ag2ZnSnSe4 (AZTSe) film with kesterite structure by using a simple solution method. A Cu2ZnSnSe4 (CZTSe)/AZTSe-based solar cell was designed and prepared by inserting AZTSe layer between CZTSe and CdS of the traditional CZTSe-based solar cell. Compared with the traditional device, an increase from 337 to 432 mV in open circuit voltage (Voc) and an accompanying rise from 3.40% to 4.72% in power conversion efficiency (PCE) were observed. To well understand the PCE improvement of the CZTSe/AZTSe-based solar cells, we calculated the band alignments of CZTSe/AZTSe and CZTSe/CdS heterojunctions using first-principles calculations, demonstrating that the CZTSe/AZTSe and CZTSe/CdS interfaces have type-II and type-I band alignments, respectively. Moreover, the band offset of AZTSe/CdS is lager than the one of CZTSe/CdS. Combined with the calculation results, the mechanism of influence of the AZTSe on the PCE improvement is discussed in detail. Our conclusions show that the addition of the AZTSe layer is a potentially applicable method to obtain CZTSe-based solar cells with higher Voc and PCE. 相似文献
2.
Liyong Yao Jianping Ao Ming-Jer Jeng Jinlian Bi Shoushuai Gao Qing He Zhiqiang Zhou Guozhong Sun Yun Sun Liann-Be Chang Jian-Wun Chen 《Nanoscale research letters》2014,9(1):678
Cu2ZnSnSe4 (CZTSe) thin films are prepared by the electrodeposition of stack copper/tin/zinc (Cu/Sn/Zn) precursors, followed by selenization with a tin source at a substrate temperature of 530°C. Three selenization processes were performed herein to study the effects of the source of tin on the quality of CZTSe thin films that are formed at low Se pressure. Much elemental Sn is lost from CZTSe thin films during selenization without a source of tin. The loss of Sn from CZTSe thin films in selenization was suppressed herein using a tin source at 400°C (A2) or 530°C (A3). A copper-poor and zinc-rich CZTSe absorber layer with Cu/Sn, Zn/Sn, Cu/(Zn + Sn), and Zn/(Cu + Zn + Sn) with metallic element ratios of 1.86, 1.24, 0.83, and 0.3, respectively, was obtained in a selenization with a tin source at 530°C. The crystallized CZTSe thin film exhibited an increasingly (112)-preferred orientation at higher tin selenide (SnSe
x
) partial pressure. The lack of any obvious Mo-Se phase-related diffraction peaks in the X-ray diffraction (XRD) diffraction patterns may have arisen from the low Se pressure in the selenization processes. The scanning electron microscope (SEM) images reveal a compact surface morphology and a moderate grain size. CZTSe solar cells with an efficiency of 4.81% were produced by the low-cost fabrication process that is elucidated herein. 相似文献
3.
Xia Wang Dong-Xing Kou Wen-Hui Zhou Zheng-Ji Zhou Si-Xin Wu Xuan Cao 《Nanoscale research letters》2014,9(1):262
In this work, we employed a convenient one-step synthesis method for synthesizing Cu2ZnSnSe4 (CZTSe) nanocrystals (NCs) in an excess selenium environment. This excess selenium situation enhanced the reaction of metal acetylacetonates with selenium, resulting in the burst nucleation of NCs at relatively low temperatures. The phase morphology and surface and optoelectronic properties of NCs before and after ligand exchange were discussed in depth. It was found that pure tetragonal-phase structure CZTSe NCs with approximately 1.7-eV bandgap could be synthesized. The removal of large organic molecules on CZTSe NCs after ligand exchange by S2− decreased the resistivity. The bandgap of the films after ligand exchange by 550°C selenization was also decreased due to better crystallinity. For potential application in CZTSe solar cells, we constructed an energy level diagram to explain the mutual effect between the absorption layer and CdS layer. Using cyclic voltammetry (CV) measurement, we found that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of CZTSe films shifted down after ligand exchange. After energy level alignment at the CdS/CZTSe interface, a type I band alignment structure was more conveniently formed after ligand exchange. This structure acted as the barrier against injection electrons from ZnO to the CZTSe layer, and recombination would subsequently be depressed. 相似文献
4.
以金属氯化物(氯化铜、氯化锌、氯化锡)为金属源,二氧化硒为前驱体,乙二醇为溶剂,在不同表面活性剂(PVP、聚氧乙烯月桂醚、聚乙二醇1 000、聚山梨酯80)和不同工艺(制备时间和制备温度)的条件下,采用溶剂热法一步合成六角片状的CZTSe纳米晶体颗粒,并采用X射线衍射仪、紫外可见分光光度计与SEM等手段对CZTSe纳米颗粒的物相、性能、形貌进行表征。实验结果表明,通过加入表面活性剂PVP并控制温度(200 ℃)和合成时间(30 h)可以取得禁带宽度约为1.5 eV、分布均匀、结构为六方片的晶粒,其与太阳能电池所需的最佳禁带宽度相近,有望在新一代太阳能电池中得到应用和推广。 相似文献
5.
The glassforming region in the system was roughly outlined and liquidus data were obtained for the three joins LiPO3 -BPO4 , Li4 P2 O7 -BPO4 , and Li3 PO4 -Li2 B4 O7 . Compatibility relations for the ternary subsystems Li4 P2 O7 -BPO4 -P2 O5 and Li2 O-Li3 PO4 -Li2 B8 O13 were established. Two ternary compounds with the probable compositions 22Li2 O - 11B2 O3 - 13P2 O5 and 2Li2 O 3B2 O3 P2 O5 were detected. 相似文献
6.
Jalajakumari Nair Padmakumar Nair Fujio Mizukami Jan G. Van Ommen Giel B. M. Doesburg Julian R. H. Ross Anthonie J. Burggraaf 《Journal of the American Ceramic Society》2000,83(8):1942-1946
Pure Al2 O3 and different compositions of La2 O3 –Al2 O3 samples have been prepared through coprecipitation. Even after heating at 1300°C, the compositions La2 O3 ·11Al2 O3 and La2 O3 ·13Al2 O3 had higher surface area compared to the pure Al2 O3 and the La2 O3 ·Al2 O3 composition. Ethanol washing is an effective way for improving the textural stability of pure Al2 O3 and La2 O3 –Al2 O3 samples. The effect of steam on the thermal stability of La2 O3 ·11Al2 O3 has also been studied. La2 O3 ·11Al2 O3 sample is found to be stable in steam. 相似文献
7.
Jian Zhang Shiwei Wang Tianjun Rong Lidong Chen 《Journal of the American Ceramic Society》2004,87(6):1072-1075
Y1.9 Er0.1 O3 and Y1.7 Yb0.2 Er0.1 O3 nanocrystalline powders were prepared via a reverse-strike coprecipitation method using nitrates and ammonia as raw materials. The obtained powders were of cubic-phase structure of Y2 O3 and the particle size was in the range of ∼60–80 nm. Strong red (4 F9/2 –4 I15/2 ) and green (2 H11/2 /4 S3/2 –4 I15/2 ) upconversion luminescence were observed in all the samples when excited with a 980-nm continuous wave diode laser. The possible upconversion mechanisms in Y1.9 Er0.1 O3 and Y1.7 Yb0.2 Er0.1 O3 were discussed. Power studies indicated that two-photon processes are responsible for the green and red upconversion luminescence in these systems. The codoping of Yb3+ greatly enhanced the red (4 F9/2 –4 I15/2 ) upconversion emission. 相似文献
8.
High-Temperature Active Oxidation of Chemically Vapor-Deposited Silicon Carbide in CO─CO2 Atmosphere
Takayuki Narushima Takashi Goto Yoshio Yokoyama Yasutaka Iguchi Toshio Hirai 《Journal of the American Ceramic Society》1993,76(10):2521-2524
Active oxidation behavior of CVD-SiC in CO─CO2 atmospheres was investigated using a thermogravimetric technique in the temperature range between 1823 and 1923 K. The gas pressure ratio, P CO2 / P CO , was controlled between 10−4 and 10−1 at 0.1 MPa. Active oxidation rates (mass loss rates) showed maxima at a certain value of P CO2 / P CO , ( P CO2 / P CO )* , In a P CO2 / P CO region lower than the ( P CO2 / P CO )* a carbon layer was formed on the SiC surface. In a P CO2 / P CO region higher than the ( P CO2 / P CO )* , silica particles or a porous silica layer was observed on the SiC surface. 相似文献
9.
Dielectric and piezoelectric properties of 0.02Pb(Y2/3 W1/3 )O3 0.98Pb(Zr0.52Ti0.48)O3 ceramics doped with additives (Nb2 O5 , La2 O3 , MnO2 , and Fe2 O3 ) were investigated. The grain sizes of these ceramics decreased with increasing amounts of additives. For additions of MnO2 and Fe2 O3 , dielectric losses decreased, while for Nb2 O5 and La2 O3 , these values increased. The maximum values of the mechanical quality factor Qm were found to be 956 and 975 for additions of 0.9 wt% Fe2 O3 and 0.7 wt% MnO2 , respectively, but donor dopants (Nb2 O5 and La2 O3 ) did not change the values of Qm . On the other hand, the piezoelectric constant d33 and the electromechanical coupling factor kp decreased with additions of MnO2 and Fe2 O3 , but improved with additions of Nb2 O5 and La2 O3 . 相似文献
10.
Keisuke Kageyama 《Journal of the American Ceramic Society》1992,75(7):1767-1771
The microwave dielectric properties and crystal structure of Ba(Zn1/3 Ta2/3 )O3 – (Sr,Ba)(Ga1/2 Ta1/2 )O3 ceramics were investigated in the present study. The Q value of Ba(Zn1/3 Ta2/3 )O3 was improved by adding 5 mol% Sr(Ga1/2 Ta1/2 )O3 . The maximum Q value of Q × f = 162000 GHz was obtained at 0.95Ba(Zn1/3 Ta2/3 )O3 . 0.05Sr(Ga1/2 Ta1/2 )O3 . For this composition, a lattice super structure caused by hexagonal ordering was observed. A further improvement in the Q value was attained when some Sr was replaced with Ba, and 0.95Ba(Zn1/3 Ta2/3 )O3 · 0.05(Sr0.25 Ba0.75 )(Ga1/2 Ta1/2 )O3 exhibited a maximum Q value such that Q × f = 210000 GHz. Despite the increased Q value with the replacement of Sr by Ba, the c/a value, which indicates the degree of lattice distortion, remained constant near 3/2. The Q value thus improved without lattice distortion in the system Ba(Zn1/3 Ta2/3 )O3 -(Sr,Ba)(Ga1/2 Ta1/2 )O3 , whereas the improvement of Q value increased with lattice distortion in the solid solution system with Ba(Zn1/3 Ta2/3 )O3 as an end member. 相似文献
11.
Tsuyoshi Honma Yasuhiko Benino Takumi Fujiwara Takayuki Komatsu Ryuji Sato 《Journal of the American Ceramic Society》2005,88(4):989-992
The glass formation region, crystalline phases, second harmonic (SH) generation, and Nd:yttrium aluminum garnet (YAG) laser-induced crystallization in the Sm2 O3 –Bi2 O3 –B2 O3 system were clarified. The crystalline phases of Bi4 B2 O9 , Bi3 B5 O12 , BiBO3 , Sm x Bi1− x BO3 , and SmB3 O6 were formed through the usual crystallization in an electric furnace. The crystallized glasses consisting of BiBO3 and Sm x Bi1− x BO3 showed SH generations. The formation of the nonlinear optical BiB3 O6 phase was not confirmed. The formation (writing) region of crystal lines consisting of Sm x Bi1− x BO3 by YAG laser irradiation was determined, in which Sm2 O3 contents were∼10 mol%. The present study demonstrates that Sm2 O3 –Bi2 O3 –B2 O3 glasses are promising materials for optical functional applications. 相似文献
12.
Emission properties and energy transfer of PbO–Bi2 O3 –Ga2 O3 –GeO2 glasses codoped with Tm3+ and Tb3+ ions were investigated. The 1.48-μm emission due to the Tm3+ :3 H4 →3 F4 transition can be used to amplify the S-band (1460–1530-nm) signal light. With Tb3+ addition, the lifetime and emission intensity of the Tm3+ :3 F4 level decreased sharply via the Tm3+ :3 F4 →Tb3+ :7 F0,1,2 energy transfer. Population densities of the 3 F4 and 3 H4 levels in Tm3+ calculated from rate equations clearly verified that population inversion in Tm3+ ions became possible with as little as 0.1 mol% of Tb3+ addition. 相似文献
13.
Phase relations in the system BaO-TiO2 from 67 to 100 mol% TiO2 were investigated at 1200° to 1450°C in O2 . Data were obtained by microstructural, X-ray, and thermal analyses. The existence of the stable compounds Ba6 Ti17 O40 , Ba4 Ti13 O30 , BaTi4 O9 , and Ba2 Ti9 O20 was confirmed. The compound BaTi2 O5 is unstable and either forms as a reaction intermediate below the solidus or crystallizes from the melt. The compounds Ba6 Ti17 O40 and Ba4 Ti13 O30 decompose in peritectic reactions, and BaTiO3 and Ba6 Ti17 O40 react to form a eutectic. Special conditions are required for the formation of Ba2 Ti9 O20 , which decomposes in a peritectoid reaction at 1420°C. The new phase diagram is presented. 相似文献
14.
Teen-Hang Meen Ying-Chung Chen Ken-Whie Liaw Hung-Duen Yang 《Journal of the American Ceramic Society》1993,76(8):1948-1952
X-ray diffraction patterns show that most samples of Y1-x Prx Ba2 Cu4 O8 examined in the present study contained a single YBa2 Cu4 O8 (1-2-4) superconductive phase for x<0.7.Lattice parameters a and b increased with Pr concentration, suggesting that most of the Pr is trivalent in Y1-x Prx- Ba2 Cu4 O8 . The zero-resistance temperature, T co , decreases monotonically from 80 K at x=0 to 12 K at x=0.65, and superconducting transition widths tend to broaden for x>0. The room-temperature resistivity changes linearly until x=0.7 and increases abruptly at x=-0.75. The critical concentration, xcr , thus was estimated to be 0.7. The effective magnetic moments of Pr in Y 1-x Prx Ba2 Cu4 O8 were 3.63., 3.35, and 3.23, μB for x=0.2, 0.4 and 0.6, respectively. In the R0.8 Pr0.2 Ba2 Cu4 O8 system, the depression of Tc weakly depends on the ionic radius of rare-earth elements. Similarities and differences between Y 1-x Prx Ba2 Cu4 O8 and Y1-x Prx- Ba2 Cu3 O7-y also were noted and are discussed in this paper. 相似文献
15.
Sergey V. Ushakov Alexandra Navrotsky Jean A. Tangeman Katheryn B. Helean 《Journal of the American Ceramic Society》2007,90(4):1171-1176
Aerodynamic levitation combined with laser heating was used to prepare melts in the HfO2 –La2 O3 (–Gd2 O3 ) systems. All melts crystallized upon quenching in oxygen. Hf2 La2 O7 pyrochlore and Gd0.5 Hf0.5 O1.75 fluorite phases were identified. Gd0.5 Hf0.5 O1.75 fluorite was transformed into the pyrochlore structure by annealing at 1450°C. Pyrochlore that crystallized from HfO2 - La2 O3 melts contained 31.6–34.2 mol% La2 O3 . The unit cell parameter increased linearly with La content from 10.736 to 10.789 Å. Drop solution calorimetric experiments were performed in 3Na2 O·4MoO3 melt at 702°C. The enthalpies of formation from the oxides for pyrochlore phases are −107.0±5.0 kJ/mol for Hf2 La2 O7 and −48.8±4.7 kJ/mol for Hf2 Gd2 O7 . The enthalpy of the pyrochlore–fluorite phase transition in Hf2 Gd2 O7 is 23.6±3.1 kJ/mol. 相似文献
16.
New layered compounds, (V0.5 Cr0.5 )3 AlC2 , (V0.5 Cr0.5 )4 AlC3 , and (V0.5 Cr0.5 )5 Al2 C3 were synthesized by reactive hot pressing V, Cr, Al, and graphite powders. The crystal structures of these new phases were determined using a combination of X-ray diffraction and scanning transmission electron microscopy. (V0.5 Cr0.5 )3 AlC2 is isotypical to Ti3 AlC2 ; while (V0.5 Cr0.5 )4 AlC3 has the Ti4 AlN3 or α-Ta4 AlC3 -type crystal structure. (V0.5 Cr0.5 )5 Al2 C3 is formed by periodically stacking of half-unit cells of (V0.5 Cr0.5 )2 AlC and (V0.5 Cr0.5 )3 AlC2 . 相似文献
17.
Satoshi Uda Etsuro Asakura Masahisa Nagashima 《Journal of the American Ceramic Society》1998,81(3):725-729
The influence of the additive SO3 on the phase relationships in the quaternary system CaO-SiO2 -Al2 O3 -Fe2 O3 was investigated by observing the change of volume ratio of 3CaOSiO2 (C3 S) to 2CaOSiO2 (C2 S) + CaO (C) in the sintered material with the increase of SO3 content. The primary phase volume of C3 S in the quaternary phase diagram shrank with the increase of SO3 and disappeared when the SO3 content exceeded 2.6 wt% in the sintered material. Changes in the peritectic reaction relationship between CaO (C), 2CaOSiO2 (C2 S), 3CaOSiO2 (C3 S), 3CaOAl2 O3 (C3 A), 4CaOAl2 O3 Fe2 O3 (C4 AF), and liquid were also observed and discussed. 相似文献
18.
The dielectric characteristics of BaBi2 Nb2 O9 , BaBi4 Ti4 O15 , BaBi8 Ti7 O27 , and La-substituted SrBi4 Ti4 O4 were investigated to discuss their ferroelectric phase transition and relaxor behaviors. BaBi2 Nb2 O9 showed typical relaxor behaviors, and a shift of T m with increasing frequency was observed in BaBi4 Ti4 O15 and SrBi4− x La x Ti4 O15 ( x =0.8, 1.0) but they underwent a real paraelectric–ferroelectric phase transition on zero-field cooling, while BaBi8 Ti7 O27 showed a normal ferroelectric nature. The reduced concentration and weakened coupling of the dipoles related to A-site bismuth are believed to be responsible for the appearance of short-range electric ordering and the relaxor behaviors in these bismuth layer-structured compounds. 相似文献
19.
Sophie Jordery William E. Lee Peter F. James 《Journal of the American Ceramic Society》1999,82(8):2239-2245
Crystallization of a series of ZnO-P2 O5 based glasses was investigated. ZnO-P2 O5 -CaO glasses could be converted most readily to glass-ceramics and crystallization of these led to formation of alpha-Zn2 P2 O7 , alpha-CaZn2 (PO4 )2 , and ß-CaZn2 (PO4 )2 phases. A further phase has been tentatively identified as monoclinic (Zn,Ca)2 P2 O7 . The most promising glass-ceramic composition Z15 (59.4ZnO·33P2 O5 ·6.6CaO·1SiO2 ) crystallized to alpha-Zn2 P2 O7 and ß-CaZn2 (PO4 )2 , the latter phase being stabilized by the presence of SiO2 which also encouraged volume nucleation giving a fine-scale (submicrometer) microstructure. 相似文献
20.
Phase relations in the system Bi2 O3 -WO3 were studied from 500° to 1100°C. Four intermediate phases, 7Bi2 O3 · WO3 , 7Bi2 O3 · 2WO3 , Bi2 O3 · WO3 , and Bi2 O3 · 2WO3 , were found. The 7B2 O · WO3 phase is tetragonal with a 0 = 5.52 Å and c 0 = 17.39 Å and transforms to the fcc structure at 784°C; 7Bi2 O3 · 2WO3 has the fcc structure and forms an extensive range of solid solutions in the system. Both Bi2 O3 · WO3 and Bi2 O3 · 2WO3 are orthorhombic with (in Å) a 0 = 5.45, b 0 =5.46, c 0 = 16.42 and a 0 = 5.42, b 0 = 5.41, c 0 = 23.7, respectively. Two eutectic points and one peritectic exist in the system at, respectively, 905°± 3°C and 64 mol% WO3 , 907°± 3°C and 70 mol% WO3 , and 965°± 5°C and 10 mol% WO3 . 相似文献