Scientific Reports
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2014
·Vol. 4
·期 1
·1-9
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IF 5.078
Zhong Jie,Xia Zhe,Luo Miao,Zhao Juan,Chen Jie,Wang Liang,Liu Xinsheng,Xue Ding-Jiang,Cheng Yi-Bing,Song Haisheng,Tang Jiang
To obtain high photovoltaic performances for the emerging copper zinc tin sulfide/selenide (CZTSSe) thin film solar cells, much effort has deservedly been placed on CZTSSe phase purification and CZTSSe grain size enhancement. Another highly crucial but less explored factor for device performance is the elemental constitution of CZTSSe surface, which is at the heart of p-n junction where major photogenerated carriers generate and separate. In this work we demonstrate that, despite the well-built phase and large grained films are observed by common phases and morphology characterization (XRD, Raman and SEM), prominent device efficiency variations from short circuited to 6.4% are obtained. Insight study highlights that the surface (0–250 nm) compositions variation results in different bulk defect depths and doping densities in the depletion zone. We propose that suitable sulfurization (at ~10 kPa sulfur pressure) drives optimization of surface constitution by managing the Cu, Zn and Sn diffusion and surface reaction. Therefore, our study reveals that the balance of elemental diffusion and interface reactions is the key to tuning the surface quality CZTSSe film and thus the performance of as resulted devices.
研究领域:
材料科学
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能源技术
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产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
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2016
·
IF 9.407
Jie Fu,Qingwen Tian,Zhengji Zhou,Dongxing Kou,Yuena Meng,Wenhui Zhou,Sixin Wu
Additional elements in the Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers can play a crucial role in improving the performance of thin film solar cells. In this paper, a significant performance enhancement of CZTSSe thin film solar cells was achieved by the partial substitution of the Zn2+ cation with Cd2+. A small amount of Cd2+ can be successfully incorporated into the host lattice of CZTSSe to form a homogeneous Cu2Zn1–xCdxSn(S,Se)4 (CZCTSSe) alloy material. We demonstrated that the crystal growth and the band gap of CZCTSSe thin films are affected by the Cd doping level. Additionally, the impact of Cd content on the space-charge density (Nc-v) and the depletion width (Wd) of CZCTSSe solar cells was systematically investigated. By this cation substitution approach, the power conversion efficiency of the solar cells based on the CZCTSSe absorber was successfully increased from 5.41 to 8.11% for the optimal composition (x = 5%).
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
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Lijian Huang,Song Wei,Daocheng Pan
Large-grained Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers are highly desirable for high-performance CZTSSe thin film solar cells. However, solution-deposited CZTSSe thin films usually consist of a large-grained top layer and a smaller-grained bottom layer. In this work, we adopt a phase-separation strategy to promote the crystal growth of the CZTSSe thin film. By choosing ZnCl2, SnCl2, CuCl (instead of CuCl2), and thiourea as the starting materials, a Cu2S/SnS/ZnS hybrid precursor thin film can be prepared, the composition of which has been testified by X-ray diffraction, X-ray photoelectron spectroscopy, Raman, and scanning electron microscopy-energy-dispersive spectrometry characterization. Owing to the volume expansion caused by Se incorporation and the high migration abilities of Cu(I) and Sn(II) ions during selenization, large-grained and compact CZTSSe films with a thickness up to 5 μm can be obtained. The corresponding thin film solar cell devices have achieved active power conversion efficiencies above 10% (8.78% for total area), much higher than those of CuCl2-based CZTSSe devices in our lab.
研究领域:
材料科学
·
能源科学
·
薄膜技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yanping Guo,Jichun Zhu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yafang Qi,Yuena Meng,Litao Han,Zhi Zheng,Sixin Wu
The kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have shown a continuous rise in power conversion efficiencies in the past years. However, the encountered interfacial problems with respect to charge recombination and extraction losses at the CdS/CZTSSe heterojunction still hinder their further development. In this work, an additional plasmonic local electric field is imposed into the CdS/CZTSSe interface through the electrostatic assembly of a two-dimensional (2D) ordered Au@SiO2 NP array onto an aminosilane-modified surface absorber. The interfacial electric properties are tuned by controlling the coverage particle distance, and the finite-difference time domain (FDTD) simulation demonstrates that the strong near-field enhancement mainly occurs near the p-n junction interface. It is shown that the imposed local electric field leads to interfacial electrostatic potential (Velec) augmentation and improves the charge extraction and recombination processes. These electric benefits enable remarkable improvements in open-circuit voltage (Voc) and short-circuit current (Jsc), leading to the cell efficiency being increased from 10.19 to 11.50%. This work highlights the dramatic role of the plasmonic local electric field and the use of the 2D Au@SiO2 NP array to modify a surface absorber instead of the extensively used ion passivation, providing a new strategy for p-n junction engineering in kesterite photovoltaics.
研究领域:
材料科学
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光伏技术
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纳米技术
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电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Energy
·
2021
·
IF 17.881
Jiazheng Zhou,Xiao Xu,Biwen Duan,Huijue Wu,Jiangjian Shi,Yanhong Luo,Dongmei Li,Qingbo Meng
Alkali metal doping, typically Li + doping, is beneficial for CZTSSe solar cells. Herein, aiming at the low solubility of conventional LiF which is hard to directly introduce into the precursor solution , an organic lithium salt (LiTFSI, lithium bis(trifluoromethanesulfonyl)imide) has been introduced into fabricating CZTSSe solar cells for the first time. 13.2% PCE (power-conversion-efficiency) with 12.7% certified PCE has been achieved with relatively higher V OC and FF, which is the highest efficiency of lithium-doping/alloying devices so far. A comprehensive investigation on the influence of LiTFSI on the formation of precursor and selenized absorber films has been carried out. The existence forms of LiTFSI in different processes are revealed as well as the relevant mechanism. That is, during selenization, LiTFSI decomposes to LiF at early stage, then LiF combines with Se to afford the Li-Se liquid fluxing intermediate, which can facilitate the phase transition and crystal growth to give compact CZTSSe films with larger grains and less pinholes, thus leading to better surface morphology and electric properties of LiTFSI doped CZTSSe absorber films. Li + doping is thus found to enable reducing interfacial defects , improving band bending and lowering V OC deficit. This work provides an easy way to precisely modify Li + salt amount in the precursor solution and subsequent CZTSSe selenization process by using organic lithium salts for high quality CZTSSe crystals and high-performance devices.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2021
·
IF 5.742
Junye Tong,Shaotong Wang,Gang Wang,Yue Liu,Yuxiang Wang,Liping Chen,Lingling Wang,Daocheng Pan,Xintong Zhang,Yichun Liu
Ion doping strategy is a promising method to enhance the efficiency of Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells, however, most of the reported works focus on studying the single ion doping in CZTSSe absorber layers . Here, Li + &Ag + and Li + &Cd 2+ double-ion-doping strategy are applied to improve the microstructure and device performances. We found that the double-ion-doping strategy can obviously increase the grain size, reduce the thickness of fine-grain layers and enhance the device performances. Furthermore, the PCEs of Li + &Ag + and Li + &Cd 2+ doped CZTSSe solar cells are up to 8.87% and 8.39%, respectively. It shows an encouraging improvement of over 43.5% and 35.8% enhancement compared with the traditional method (6.18%), and significantly higher than single ion doping strategy (7.60%, 7.99% and 7.11% for Li + , Ag + , and Cd 2+ doped CZTSSe solar cells). This work provides a new solution to improve the microstructure and device performances of CZTSSe solar cells.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Jingyuan Guo,Lei Wang,Letu SiQin,Chenjun Yang,Yutian Wang,Yiming Wang,Shuyu Li,Ruijian Liu,Chengjun Zhu,Hongmei Luan
Compared with the traditional structure, the new Cu 2 ZnSn(S, Se) 4 (CZTSSe) solar cell without ZnO window layer has a larger short-circuit current reduction. Due to the poor band matching, serious interface recombination exists at the CZTSSe/CdS heterojunction interface. We have designed a strategy for the preparation of CdS(In) buffer layers by In ion doping to increase the depletion layer width, enhance the carrier concentration in the CdS(In) buffer layer, and improve the energy band alignment problem at the interface of the CZTSSe/CdS heterojunction , which in turn reduces the J SC loss caused by the removal of the ZnO layer. The energy band alignment of the CZTSSe/CdS heterojunction was modulated by finely controlling the doping amount of In ions, which decreased the conduction band offset (CBO) from 0.32 eV to 0.28 eV. Good band alignment is more conducive to carrier separation and transport, and reducing the nonradiative charge recombination at the CZTSSe/CdS heterojunction interface can effectively improve the J SC . Based on the contribution of device electrical parameters to photoelectric conversion efficiency (PCE), the contributions of J SC , open-circuit voltage, and fill factor were calculated to be 107.56%, -6.89%, and -0.67%, respectively, which indicates that the method significantly improves short-circuit currents and reduces the loss of J SC due to the absence of ZnO layer. This study provides a method to achieve high-efficiency CZTSSe solar cells by optimizing the energy band matching of CZTSSe/CdS heterojunctions from 7.07% PCE in conventional cells to 9.01% PCE in novel cells.
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Afei Zhang,Zhaoyang Song,Zhengji Zhou,Yueqing Deng,Wenhui Zhou,Shengjie Yuan,Dongxing Kou,Xin Zhang,Yafang Qi,Sixin Wu
Interfacial properties play a significant role in the photovoltaic performance of kesterite solar cells. Different from its predecessor of Cu(In,Ga)S(e)2, the interface between Cu2ZnSnS(e)4 (CZTSSe) and the back contact electrode of Mo is chemically unstable during selenization of the absorbing layer at high temperature. Raman spectra reveal that the MoS2 interfacial layer is easily formed because of more negative change of free energy. However, in reality, the band offset between CZTSSe and MoS2 is unfavorable for hole transfer. By selenizing the Mo electrode, the as-prepared MoSe2 interfacial layer can suppress the diffusion of S and improve the band structure, which is beneficial for charge carrier separation and transfer. Therefore, the conversion efficiency of CZTSSe solar cells is increased from 10.28 to 11.46%.
研究领域:
光伏
·
材料科学
·
半导体界面
·
可再生能源
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2026
·
IF 2.4
Shulei Liang,Yingjun Zhou,Yujun Li,Chuanhe Ma,Hailong Wang
This study investigated the impact of MoOx blocking layer prepared by magnetron sputtering and air-annealing methods on the photoelectric performance of CZTSSe solar cells. The results showed that the MoO2 layer prepared by sputtering method exhibited more uniform and dense surface morphology, with an optimal thickness of 10 nm for the cell's photoelectric performance. The electrochemical impedance spectroscopy (EIS) analysis revealed that the MoO2 blocking layer effectively suppressed carrier recombination, increasing the recombination resistance (Rct) from 4516 Ω to 11342 Ω and significantly enhancing the minority carrier lifetime (τ) from 32 μs to 146 μs. Additionally, light response (I-T) testing demonstrated that devices with the MoO2 blocking layer achieved a peak photocurrent (Imax) four times higher than that of the control group under high duty cycle (PWM=90%), with an outstanding on/off ratio of 7×10 5 and a shortened pulse rise time (τrising) of 2 μs.These results confirm that the MoO2 blocking layer markedly enhanced carrier mobility and dynamic response by effectively suppressing the formation of MoSe2 and mitigating the decomposition of the CZTSSe absorber layer. Consequently, the device's power conversion efficiency (PCE) was boosted from 8.26% to 11.45%. This work provides valuable insights into interface engineering for developing high-performance CZTSSe photovoltaic devices.
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Qing Zhou,Meinan Yan,Yuzhou Sun,Yujiao Ma,Zihan Zhang,Haoyu Xu,Xiaoyun Teng,Chao Gao,Wei Yu
In this paper, we reported a novel precursor solution for the preparation of Cu 2 ZnSn(S,Se) 4 (CZTSSe) film. Large-grain monolayer CZTSSe film can be obtained by using the precursor solution. The influence of selenization temperature on the properties of CZTSSe films and solar cells were investigated. We found the monolayer CZTSSe film can be prepared with the selenization temperature as low as 510 °C. While an increased selenization temperature was used, the size of the crystalline grains in CZTSSe film increased significantly, but the decomposition of CZTSSe material got more serious. As the increase of the selenization temperature, increased short-circuit current (J SC ) can be achieved for the fabricated solar cell, which could be caused by the improved crystallinity of CZTSSe layer and the enlarged depletion width of solar cell (as much as 391 nm). On the other hand, the open-circuit voltage (V OC) decreased as the increase of selenization temperature, which may relate with the decomposition of CZTSSe material. The best solar cell achieved the efficiency of 11.4% (active area), which was based on CZTSSe film with the selenization temperature of 510 °C.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Xiangyang Zhao,Lingling Wang,Yawei Wang,Xingyu Zhang,Rong Fang,Yue Zhou,Rui Guo,Xintong Zhang,Yichun Liu
Kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin film solar cells are considered a promising new type of film cell, due to their rich elemental reservation and excellent photovoltaic performance. However, the deleterious defects at the heterojunction interface severely hinder charge transport, separation, and extraction, significantly limiting the photovoltaic performance of CZTSSe solar cells. In this study, a simple method involving the incorporation of Cd 2+ and Ag + dual-ion at the heterojunction interface was proposed to reduce interfacial defects. The results showed that Cd 2+ and Ag + dual-ion interface deposition effectively reduced the [2Cu zn + Sn zn ] harmful defects near the heterojunction interface and subsequently reduced the number of recombination centers in the interface. This led to improved carrier recombination at the interface. Meanwhile, the devices achieved a wider depletion width, which was more favorable for carrier collection. Ultimately, the conversion efficiency increased by 32.81 %. This simple interface dual-ion deposition strategy offers a promising strategy for further enhancing the efficiency of CZTSSe cells.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yue Liu,Chunkai Wang,Ding Ma,Mengge Li,Yuting Sun,Xiaofei Sun,Yan Zhu,Bin Yao,Yongfeng Li,Zhanhui Ding
It is proved that secondary phases, such as Cu 2 Se, and ZnSe etc., and MoSe 2 layer can form at Cu 2 ZnSn(S,Se) 4 (CZTSSe)/Mo electrode interface, due to that Mo electrode reacts with CZTSSe and Se vapor during selenization process. The secondary phases and MoSe 2 with inappropriate thickness can decrease power conversion efficiency (PCE) of CZTSSe solar cell. In this work, a simple method was proposed to suppress the reaction between CZTSSe and Mo, and to optimize the thickness of MoSe 2 . This was achieved by growing a layer of Mo oxide in situ on the Mo electrode surface through soaking the Mo electrode in H 2 O 2 . The Mo oxide layer consisted of MoO 3 , MoO x and MoO 2 . It could suppress the reaction between Mo and CZTSSe, thus preventing the formation of secondary phases in CZTSSe. By further tuning the soaking time, the thickness and density of the Mo oxide layer were optimized, resulting in an optimized thickness of the MoSe 2 layer and a significant improvement in the contact quality at both the front and back interfaces. This improvement is beneficial for suppressing carrier recombination and reducing contact resistance. Furthermore, the Cu/(Zn+Sn) ratio in CZTSSe was optimized, leading to an expansion of the depletion region width. As a result, the reverse saturation current density and series resistance decrease, while the photogenerated current density increases. This ultimately led to a rise in PCE from 7.66% for CZTSSe solar cells with Mo electrodes that were not soaked to 8.95% for those with Mo electrodes soaked for 20 s.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
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