SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Jiayong Zhang,Bin Yao,Zhanhui Ding,Yongfeng Li,Ding Ma,Mengge Li,Yuting Sun,Chunkai Wang,Yue Liu,Xiaofei Sun
Although trace silver (Ag) substitution for Cu in Cu 2 ZnSn(S, Se) 4 (CZTSSe) offers benefits in improving open-circuit voltage (V OC ) of CZTSSe solar cells, its further development is still hindered by the fairly low short-circuit current density (J SC ) owing to the increase of bandgap (E g ) of the absorber layer . Herein, a strategy is demonstrated to mitigate the poor J SC arising from the Ag substitution by tuning the Cu 2+ /(Cu + +Cu 2+ ) percentage in the (Cu, Ag) 2 ZnSnS 4 (CAZTS) precursor solution . Depth characterization indicates that the appropriate Cu 2+ /(Cu + +Cu 2+ ) percentage in the CAZTS precursor solution increases the photogenerated charges separation and carrier transport processes for Ag-substituted CZTSSe (CAZTSSe) solar cells. Benefiting from this strategy, the power conversion efficiency (PCE) of 9.57% is achieved when the Cu 2+ /(Cu + +Cu 2+ ) is 50 at.%. The main factor for the improvement of PCE is due to the increase in photogenerated current density (J L ) and decrease in shunt resistance (R sh ). It is demonstrated that the increase in J L results from a widening in the depletion layer width (W d ) of the p-n junction and an increase in carrier lifetime, induced by optimization of the Cu 2+ /(Cu + +Cu 2+ ) percentage. While the decrease in R sh comes from the change of reaction pathways due to the change in Cu 2+ /(Cu + +Cu 2+ ) percentage.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2021
·
IF 5.742
Ting Wang,Jiayong Zhang,Bin Yao,Yongfeng Li,Zhanhui Ding,Chunkai Wang,Jia Liu
Five types of Cu 2 ZnSn(S,Se) 4 (CZTSSe) films were fabricated by selenization of Cu 2 ZnSnS 4 (CZTS) precursor films preparing through Cu-Zn-Sn-S precursor solutions with nominal Cu + /(Cu + +Cu 2+ ) ratio of 0, 0.2, 0.4, 0.8 and 1. Five types of CZTSSe solar cells were prepared by using the five types of CZTSSe films as absorbers, respectively. The crystal quality and phase composition of the CZTS and CZTSSe films were characterized by XRD, Raman and SEM, and the photovoltaic performance for the CZTSSe solar cells were measured by J-V and EQE. It is found that the CZTS film consists of kesterite CZTS when the ratio is 0 and of kesterite CZTS together with a small amount of SnS when the ratio is 0.2 to 1. All of the CZTSSe films are comprised of kesterite CZTSSe and a small amount of Zn(S,Se). The crystal quality and lattice constants of the kesterite CZTSSe increase with increasing the ratio, while the amount of Zn(S,Se) decreases with increasing the ratio and almost to zero as the ratio is 1. The power conversion efficiency ( PCE ) of the CZTSSe solar cells increases from 5.47% to 8.43% as the ratio increases from 0 to 1, which is due to improvement in short-circuit current density ( J sc ) and filling factor ( FF ) and decrease in open circuit voltage deficit ( V oc , def ). The influence mechanism of the ratio on the PCE is suggested by analyzing effect of the ratio on electrical parameters of the CZTSSe solar cells.
研究领域:
光伏技术
·
材料科学
·
半导体薄膜
·
太阳能电池技术
✓ 已验证
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Lei Meng,Bin Yao,Yongfeng Li,Zhanhui Ding,Zhenyu Xiao,Kaisi Liu,Gang Wang
The back contact adhesion is the important factor of the microstructural performance which can determine the optoelectronic properties of the kesterite-based solar cells. Here, we present a rational and effective strategy to significantly enhance the back contact adhesion of Cu 2 (Zn,Cd)Sn(S,Se) 4 (CZCTSSe) absorber layers by insetting the appropriate thickness carbon-doping CZCTS thin films . We chose the oleylamine as the carbon-doping reagent which can generate a small amount of carbon in the annealing process . The suitable thickness carbon-doping CZCTS films can significantly change the crystal growth mechanism of CZCTSSe absorber layers, and eliminate the holes in the back contact. The efficiency of CZCTSSe solar cells fabricated by insetting the appropriate thickness carbon-doping CZCTS films is above 7%, and shows the excellent repeatability and long-term air stability compared with the control devices.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
表面与界面工程
·
无机功能材料
✓ 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
Energy & Environmental Science
·
2017
·Vol. 10
·期 11
·2401-2410
·
IF 29.518
Ya-Fang Qi,Dong-Xing Kou,Wen-Hui Zhou,Zheng-Ji Zhou,Qing-Wen Tian,Yue-Na Meng,Xin-Sheng Liu,Zu-Liang Du,Si-Xin Wu
Although the substitution of Cu by Ag to suppress CuZn defects offers several advantages in overcoming the large open-circuit voltage (Voc) deficit for Cu2ZnSn(S,Se)4 (CZTSSe) solar cells, an excellent performance has not been achieved to date primarily due to the Fermi level pinning at the CdS/absorber interface and large recombination at the absorber/Mo interface. Herein, we developed a composition grading strategy to achieve a V-shaped Ag-graded structure with a higher Ag content on both the back and front surfaces of the (Cu,Ag)2ZnSn(S,Se)4 (CAZTSSe) layer. The key advantages of this Ag-graded structure are as follows: the higher content towards the CdS/absorber interface can create weak n-type donor defects and retard Fermi level pinning, whereas the lower content at the interlayer maintains the conductivity and light absorption; moreover, the other higher content towards Mo back contact can effectively suppress the recombination and improve the utilization of long-wave incident light. By appropriately adjusting the Ag gradient, we demonstrated a significant increase in Voc, and an unexpected conversion efficiency of 11.2% was achieved. This is the highest efficiency achieved to date for Ag-substituted CZTSSe solar cells, and the result supports a new aspect that synthesis of a composition-graded CAZTSSe absorber has great potential for future research.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Yanchun Yang,Lijian Huang,Daocheng Pan
In our recent report (ACS Appl. Mater. Interfaces2016, 8, 5308), Li+ ions had been successfully incorporated into the lattice of the selenized Cu2ZnSn(S,Se)4 thin film on a quartz substrate by substituting equivalent Cu+ ions, and Li+ ions was also found to have the little effect on the crystal growth and defect passivation. To further improve the cell performance of Li-doped CZTSSe devices, we conducted the same experiments on the sodium-rich soda-lime glass (SLG) substrate in this study, instead of sodium-free quartz substrate. Surprisingly, only trace amounts of Li (Li/Cu molar ratio ∼1 × 10–4) were detected in the final CZTSSe thin films; meanwhile, a large amount of sodium was present on the surface and at the grain boundaries of the selenized thin films. A Li/Na exchange mechanism is used to explain this phenomenon. Only on the sodium-free substrate can Li+ ions enter the CZTSSe host lattice, and doping Li+ ions on the SLG substrate are nearly identical to doping Na+ ions.
研究领域:
材料科学
·
太阳能电池
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 9
·期 1
·413-422
·
IF 11.301
Xiaohuan Chang,Junjie Fu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yafang Qi,Zhi Zheng,Sixin Wu
The introduction of alkali metal (AM) post-deposition treatment (PDT) has led to the consecutive breakthrough of world record efficiencies for Cu(In,Ga)Se2 photovoltaics. However, for the derivative Cu2SnZn(S,Se)4 (CZTSSe) solar cells, the corresponding verdict seems partially unjustified due to the difference in defect chemical environment and phase structure, and the most effective incorporation means of AMs is still a mystery. In this work, for the first time, we developed a dual AM synergistic incorporation strategy combining light and heavy AMs by post-depositing CsF after NaF-PDT to improve the efficiency of CZTSSe solar cells. The relevant microscopic-electrical advantages with regard to the different roles of NaF and CsF PDT are discussed in more detail. It was found that the Na atoms are randomly dispersed both in the grain interior (GI) and grain boundaries (GBs), significantly increasing the acceptor concentration and passivating the deep level defects to enhance the Voc. In contrast, the Cs atoms are mainly segregated at the GBs, primarily increasing the potential of the GBs and improving the FF. The prominent electric benefits of Cs at the GBs and Na in the GI finally increase the device efficiency from 10.12% to 12.16%. Our findings solve the difficulty in obtaining the available Voc and FF for future high efficiency research and should serve as a basis for the in-depth understanding of AM-PDT in kesterite photovoltaics.
研究领域:
材料科学
·
光伏技术
·
半导体物理
✓ 已验证
产品关联
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
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yanping Song,Bin Yao,Yongfeng Li,Zhanhui Ding,Huanhuan Sun,Zhenzhong Zhang,Ligong Zhang,Haifeng Zhao
Cu2ZnSn(S,Se)4 (CZTSSe) thin-film solar cells have been encountering a bottleneck period since the champion power conversion efficiency (PCE) of 12.7% was achieved by Kim et al. in 2014. One of the critical factors that impede its further development is the relatively low open-circuit voltage (VOC) caused by serious interface carrier recombination. In this regard, back surface field (BSF) employment is a feasible strategy to address the VOC issue of CZTSSe solar cells to some extent. Here, we demonstrated a self-organized BSF introduced by prompting interfacial MoSe2 layer transition from inherent n-type to desirable p-type with Nb doping (p-MoSe2:Nb). The BSF application can significantly reduce the carrier recombination at the back electrode interface (BEI) and lower down the back contact barrier height. The PCE of the corresponding cell was improved from 4.72 to 7.15% because of the enhancement of VOC and fill factor, primarily stemming from the doubling aspects of increased shunt resistance (RSh), decreased series resistance (RS), and alleviative recombination velocity of the BEI induced by the BSF. Our results suggest that introducing a BSF fulfilled with p-MoSe2:Nb is a facile and promising route to improve the performance of CZTSSe thin-film solar cells.
研究领域:
光伏技术
·
薄膜太阳能电池
·
半导体材料
·
材料科学
·
可再生能源
✓ 已验证
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-9
·
IF 16.6
Xu Xiao,Zhou Jiazheng,Yin Kang,Wang Jinlin,Lou Licheng,Jiao Menghan,Zhang Bowen,Li Dongmei,Shi Jiangjian,Wu Huijue,Luo Yanhong,Meng Qingbo
Kesterite Cu 2 ZnSn(S, Se) 4 is considered one of the most competitive photovoltaic materials due to its earth-abundant and nontoxic constituent elements, environmental friendliness, and high stability. However, the preparation of high-quality Kesterite absorbers for photovoltaics is still challenging for the uncontrollability and complexity of selenization reactions between metal element precursors and selenium. In this study, we propose a solid-liquid/solid-gas (solid precursor and liquid/vapor Se) synergistic reaction strategy to precisely control the selenization process. By pre-depositing excess liquid selenium, we provide the high chemical potential of selenium to facilitate the direct and rapid formation of the Kesterite phase. The further optimization of selenium condensation and subsequent volatilization enables the efficient removal of organic compounds and thus improves charge transport in the absorber film. As a result, we achieve high-performance Kesterite solar cells with total-area efficiency of 13.6% (certified at 13.44%) and 1.09 cm 2 -area efficiency of 12.0% (certified at 12.1%).
研究领域:
材料科学
·
光伏技术
·
太阳能
·
半导体物理
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）