Crystals
·
2019
·Vol. 9
·期 9
·474
·
IF 2.061
Xunan Shen,Chengchun Tang,Chao Zhang,Guanda Li,Yue Zhao,Wei Li,Guifeng Chen,Tie Yang
In current work, Cu2ZnSn(S,Se)4thin films have been prepared by the sol-gel method based on dimethyl sulfoxide solution followed by a modified three-step selenization process. The key process of this method is to divide the Se evaporation and annealing into two different stages: employ a thermal cracking Se source in the Se evaporation stage and an above-atmospheric pressure in the annealing process. The morphological, structural, elemental distributional, and photovoltaic properties of Cu2ZnSn(S,Se)4thin films prepared with the three-step selenization process were systematically investigated. It was found that through this modified selenization process, the formations of secondary phases (ZnSe, CuSnSe3) and a fine-grain bottom layer, which usually exists in the traditional one-step selenization process, were effectively suppressed. These improvements could further reduce the carrier recombination and improve the solar cell performance. The best solar cell is obtained with a short-circuit current density of 28.16 mA/cm2, open-circuit voltage of 404.91 mV, fill factor of 62.91%, and a power conversion efficiency of 7.17% under air mass 1.5 (100 mW/cm2) illumination.Keywords:CZTSSe solar cell;sol-gel method;selenization;thermal cracking Se;above-atmospheric pressure;secondary phases
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
Science Bulletin
·
2020
·
IF 9.511
Linbao Guo,Jiangjian Shi,Qing Yu,Biwen Duan,Xiao Xu,Jiazheng Zhou,Jionghua Wu,Yusheng Li,Dongmei Li,Huijue Wu,Yanhong Luo,Qingbo Meng
Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu 2 ZnSn(S, Se) 4 (CZTSSe) solar cells. The key is to find an appropriate molecular agent to prepare a stable solution and optimize the coordination structure to facilitate the subsequent crystallization process . Herein, we introduce thioglycolic acid (TGA), which possesses strong coordination (SH) and hydrophilic (COOH) groups, as the agent and use deprotonation to regulate the coordination competition within the aqueous solution. Ultimately, metal cations are adequately coordinated with thiolate anions , and carboxylate anions are released to become hydrated to form an ultrastable aqueous solution. These factors have contributed to achieving CZTSSe solar cells with an efficiency as high as 12.3% (a certified efficiency of 12.0%) and providing an extremely wide time window for precursor storage and usage. This work represents significant progress in the non-toxic solution fabrication of CZTSSe solar cells and holds great potential for the development of CZTSSe and other metal sulfide solar cells.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 42
·22065-22074
·
IF 11.301
Hongling Guo,Gang Wang,Rutao Meng,Yali Sun,Siyu Wang,Shengli Zhang,Jianyu Wu,Li Wu,Guangxing Liang,Hui Li,Yi Zhang
A Li+-doping strategy is a promising route for achieving highly efficient Cu2ZnSn(S,Se)4 (CZTSSe) photovoltaic devices with a large grain absorber layer, high p-type carrier concentration and good band alignment at the Cu2ZnSn(S,Se)4/CdS interface. However, Li+-doped CZTSSe solar cells based on in situ and pre-deposition doping strategies reported thus far generally suffer from massive lithium losses and sodium rejection due to the soda-lime glass substrate. Therefore, simultaneously fulfilling the goals of simple and efficient Li+-doping remains a major technical challenge, which may be addressed, as we demonstrate here, with the development of a Se&LiF co-selenization process. By engineering the band alignment of the Cu2ZnSn(S,Se)4/CdS interface through the Se&LiF co-selenization process, an encouraging efficiency of 11.63% with an open-circuit voltage deficit of 0.583 V has been reached. Furthermore, the crystallinity of the absorber layer and the distribution of copper are improved, and a more copper-poor CZTSSe surface is formed. This novel Li+-doping strategy introduces a new approach towards the goal of high-performance CZTSSe solar cells compatible with a simple manufacturing process and excellent performance.
研究领域:
材料科学
·
光伏技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Energy
·
2023
·Vol. 8
·期 5
·526-535
·
IF 56.7
Zhou Jiazheng,Xu Xiao,Wu Huijue,Wang Jinlin,Lou Licheng,Yin Kang,Gong Yuancai,Shi Jiangjian,Luo Yanhong,Li Dongmei,Xin Hao,Meng Qingbo
The control of the phase evolution during the selenization of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) is crucial for efficient solar cells. Here, we regulate the phase-evolution kinetics of Ag-alloyed CZTSSe by applying a positive pressure in the reaction chamber at the initial stage of the annealing process. The partial pressure of Se decreases, reducing the collision probability between selenium molecules and the kesterite precursor during the initial formation of the crystals. This results in the precursor transforming into CZTSSe in a single step, without the formation of secondary phases. CZTSSe forms at relatively higher temperature than conventional methods, leading to high-crystallinity kesterite films with fewer defects. We demonstrate solar cells with a total area efficiency of 14.1% and a certified total area efficiency of 13.8%. This work provides insights into the selenization mechanism and phase evolution of kesterite absorbers, enabling efficient solar cells.
研究领域:
材料科学
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太阳能
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2019
·
IF 4.674
Huiling Cai,Liquan Yao,Yingsen Xia,Chunyan Dao,Jianmin Li,Limei Lin,Zhiping Huang,Guilin Chen
In this work, a three-step (sulfurization-selenization-sulfurization) annealing process was designed to optimize the surface constitution of Cu 2 ZnSn(S, Se) 4 (CZTSSe) thin films, which was prepared by oxide nanoparticles-based approach. The devices with the Mo/CZTSSe/CdS/ZnMgO/ZnO:Al/Al structure were fabricated and their performances were studied. The additional post-sulfurization with low toxicity sulfur powder has negligible impact on the structure, morphology and composition of CZTSSe bulk, however, it improves open circuit voltage of device significantly. The open circuit voltage can be increased significantly from 408 mV (without surface sulfurization) to 497 mV (with surface sulfurization). This is benefited from the increase of surficial sulfur content and the broadening of the surface band-gap of the CZTSSe thin film. The result is confirmed by X-ray photoelectron spectroscopy analysis. Such a crucial three-step annealing process promotes the power conversion efficiency from 4.71% (2-step) to 6.37% (3-step), which is the champion efficiency of oxide precursor derived CZTSSe solar cell.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Wangen Zhao,Fengyang Yu,Shengzhong Frank Liu
The development of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells determines the prospect of thin-film photovoltaic devices because of some of their strengths. However, the usual solution fabrication processes of CZTSSe absorbing layers are either too tedious or highly toxic. Here, we have developed an alternative strategy to prepare kesterite CZTSSe absorber films with a simple and low-toxicity solution process by replacing the commonly employed thiol-based compounds using the glycolic acid aqueous solution, which significantly reduces the environment pollution and toxicity, providing a possibility toward the green solvent process. The power conversion efficiency of 6.81% has been acquired based the aqueous solution-processed CZTSSe thin film via optimizing the fabrication technology.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY
·
2023
·
IF 6.7
Chunkai Wang,Bin Yao,Yongfeng Li,Zhanhui Ding,Ding Ma,Ting Wang,JiaYong Zhang,Dongxu Zhang,Yue Liu,Ruijian Liu
The physical properties of CdS buffer layers and the interface quality between CdS layer and Cu 2 ZnSn(S,Se) 4 (CZTSSe) absorber have a significant impact on the performance of CZTSSe solar cells. In the present work, five types of CZTSSe solar cells with conventional structure (denoted as CdS- x -cells, x = 55, 60, 65, 70 and 75) were fabricated by using CdS prepared at deposition temperatures of 55, 60, 65, 70 and 75 ℃, respectively, as buffer layer, and influence mechanism of the deposition temperature of CdS layers on power conversion efficiency (PCE) of the CdS- x -cells was investigated. It is found that the PCE of the CdS- x -cells increases from 8.52% to 10.36% as the deposition temperature rises from 55 to 60 ℃ but falls from 10.36% to 7.14% from 60 to 75 ℃. The analysis on the photovoltaic and electrical parameters indicates that the increase in PCE is predominantly derived from the decreased reverse saturated current density (J 0 ), followed by the decreased series resistance (R S ) and increased shunt resistance (R Sh ). The decreased PCE with the further increasing deposition temperature is mainly contributed from the increased J 0 , followed by the decreased R Sh and photogenerated current density (J L ). The influence mechanism of deposition temperature of the CdS layer on PCE is suggested via quantitatively analysis of influence of electrical, optical properties and crystal quality of CdS prepared at various deposition temperatures on J L and electrical parameters of CdS- x -cells. This work is helpful for improvement of PCE of CZTSSe solar cells by modification of properties of buffer layer.
研究领域:
材料科学
·
光伏技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Ruixin Ma,Fan Yang,Shina Li,Xiaoyong Zhang,Xiang Li,Shiyao Cheng,Zilin Liu
CZTSSe is an important earth abundant collection of materials for the development of low cost and high efficiency thin film solar cells. This work developed a simple non-vacuum-based route to fabricate CZTSSe absorber films. This was demonstrated by first synthesizing Cu 2 ZnSnS 4 (CZTS) nano-crystalline based on solid-phase synthesis. Then a stable colloidal ink composed of CZTS nano-crystalline was blade coated on Mo-coated substrates followed by an annealing process under Ar atmosphere. After CZTS films formation, the films were sintered into CZTSSe absorber films by exposing them under Selenium vapor. The formation of a kesterite type CZTS was confirmed using X-ray diffraction and Raman scattering measurements. The band gap of CZTSSe absorber films was determined to be 1.26 eV, which was appropriate for use as an absorber layer in thin film solar cells. The CZTSSe absorber films showed a good photovoltatic performance, demonstrating this simple approach had great potential for CZTSSe solar cell production.
研究领域:
材料科学
·
光伏技术
·
薄膜技术
·
纳米材料
·
可再生能源
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 9
·期 4
·2292-2300
·
IF 11.301
Yafang Qi,Xiaoyue Zhao,Yao Liu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yuena Meng,Sixin Wu
In Cu2ZnSn(S,Se)4 photovoltaic devices, the exceptionally high density of 2CuZn + SnZn donor defects may induce bandgap fluctuations and thus limit Voc and PCE enhancement. We have previously reported that the partial substitution of Ag for Cu in Cu2ZnSn(S,Se)4 provides a promising way to effectively suppress CuZn defects and considerably enhance the cell performance for Cu2ZnSn(S,Se)4 photovoltaic devices. However, the bandgap fluctuations and detrimental band tailing fundamentally still limit cell performance. On the basis of a Ag-substituted CZTSSe system, in this paper, we demonstrate that partially substituting Zn with Mn could be a feasible tactic to pronouncedly decrease the bandgap fluctuations and prevent detrimental band tailing. Our in-depth investigation reveals that Mn substitution could increase depletion width, decrease the defect densities of the CuZn acceptor and 2CuZn + SnZn donor, and enable grain boundary (GB) inversion in a (Cu,Ag)2ZnSn(S,Se)4-based cell. As a result, an impressive PCE of 11.81% was achieved when the Mn substitution level was 10%, with a Voc of 478 mV, a Jsc of 37.89 mA cm−2, and an FF of 65.23%. This is so far the highest efficiency among Mn-substituted CZTSSe-based photovoltaic devices. By thoroughly understanding these photoelectric properties of the CZTSSe-based photovoltaic devices, we believe that the breakthrough in device efficiency will come soon through our continuous efforts.
研究领域:
材料科学
·
光伏技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 33
·期 3
·2210551
·
IF 19.924
Hang Geng,Mengyang Wang,Songfan Wang,Dongxing Kou,Zhengji Zhou,Wenhui Zhou,Yafang Qi,Shengjie Yuan,Litao Han,Yuena Meng,Sixin Wu
Abundant intrinsic defects and defect clusters in Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells lead to severe nonradiative recombination and limited photoelectric performance. Therefore, developing effective method to suppress the detrimental defects is the key to achieve high-efficiency solar cell. Herein, a convenient two-step cooling strategy in selenization process is reported to suppress the Cu Zn and Sn Zn defects and defect clusters synergistically. The results show that rapid cooling during section from selenization temperature to turning temperature can inhibit the volatilization of Sn and restrain the corresponding Sn-related defects, while slow cooling during the subsequent temperature section can reduce the degree of Cu-Zn disorder. Benefitting from the synergistic effect of two-step cooling, a significantly lowered concentration of Sn Zn and Cu Zn defect and their defect clusters [2Cu Zn +Sn Zn ] in absorber is observed, meanwhile, a reduced band tailing effect and promoted carrier collection efficiency of the photovoltaic device is obtained. Finally, a device with improved open-circuit voltage ( V oc ) of 505.5 mV and efficiency of 12.87% is achieved. This study demonstrates the impact of cooling process on defects controlling for the first time and provides a simple and effective new strategy for intrinsic defect control, which may be universal in other inorganic thin film solar cells.
研究领域:
材料科学
·
太阳能技术
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Zhao Benhui,Deng Yueqing,Cao Lei,Zhu Jichun,Zhou Zhengji
Kesterite-structured Cu2ZnSn(S,Se)4 (CZTSSe) thin film photovoltaics have attracted considerable attention in recent years because of its low-cost and eco-friendly raw material, as well as high theoretical conversion efficiency. However, its photovoltaic performance is hindered by large open-circuit voltage (VOC) deficiency due to the presence of intrinsic defects and defect clusters in the bulk of CZTSSe absorber films. The doping of extrinsic cation to the CZTSSe matrix was adopted as an effective strategy to ameliorate defect properties of the solar cell absorbers. Herein, a novel Se&Sb2Se3 co-selenization process was employed to introduce Sb into CZTSSe crystal lattice. The results reveal that Sb-doping plays an active role in the crystallization and grain growth of CZTSSe absorber layer. More importantly, one of the most seriously detrimental SnZn deep defect is effectively passivated, resulting in significantly reduced deep-level traps and band-tail states compared to Sb free devices. As a result, the power conversion efficiency of CZTSSe solar cell is increased significantly from 9.17% to 11.75%, with a VOC especially enlarged to 505 mV from 449 mV. This insight provides a deeper understanding for engineering the harmful Sn-related deep defects for future high-efficiency CZTSSe photovoltaic devices.
研究领域:
材料科学
·
光伏技术
·
半导体物理
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 7
·3135-3142
·
IF 10.733
Xiangyun Zhao,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Yuena Meng,Qingbo Meng,Zhi Zheng,Sixin Wu
Although low-temperature selenization technology offers several advantages in terms of production costs and beneficial composition profile controlling for Cu2ZnSn(S,Se)4 (CZTSSe) solar cells, excellent performance has not yet been achieved primarily due to the increased number of electronic disorders, smaller grain sizes, and more grain boundaries. In this study, a universal strategy for significantly increasing the power conversion efficiency (PCE) of low-temperature processed CZTSSe solar cells through directly dissolving the fluxing agent antimony into the as-prepared precursor solution is demonstrated. The key feature of this approach is that Sb atoms actually act without entering into the lattice and leave almost no residue within the absorber after taking effect. By appropriately adjusting the antimony incorporation concentration, the grain size, fine-grain layer thickness, local defect chemistry environment, and hole carrier concentration can be simultaneously improved, especially at low temperatures. More importantly, a larger band bending around the grain boundary (GB) is also observed by increasing the potential value from 40 mV to 100 mV after antimony incorporation, which can facilitate the GB-dominated carrier separation process. Due to the antimony-assisted morphology and enhancement in the nanoscale electrical properties, the CZTSSe device could maintain its performance at a lower temperature of 80 °C and directly decrease the selenization temperature down to 470 °C. This systematic study presents a new aspect for overcoming the challenges encountered at low temperatures, and our findings further support the great feasibility for the future application of low-temperature-processed CZTSSe photovoltaic technology to meet the industrial-scale production standards.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子