MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2023
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IF 4.1
Jing Zhao,Fangfang Wu,Xiuxun Han
Precursor design plays an important role in preparing high-quality Cu 2 ZnSn(S, Se) 4 (CZTSSe) absorber layers via solution coating method. In this work, SnCl 4 and SnCl 2 with different molar ratios were utilized as Sn source in the precursor solution to investigate effects of Sn oxidation state on the film growth process and the related solar cell device performance. Sn 4+ -rich and Sn 2+ -rich precursors were found to follow different reaction paths in obtaining CZTSSe grains, thus resulting in quite different crystallinity and morphology of the absorber. For Sn 4+ -rich precursor system, the direct Se substitution reaction of macroscopically disordered CZTS precursor calls for relatively high temperature to eliminate the double-layer structure and form large-size CZTSSe grains. For Sn 2+ -dominated precursor solution, however, the reaction of binary compound phases with the catalysis of low-melting-point Sn(S, Se) 2 prefers relatively low temperature during the selenization process. The work demonstrates that both types of precursors (or reaction paths) could actually lead to high-quality CZTSSe absorbers and solar cell devices with conversion efficiency higher than 8%, upon the proper selection of selenization conditions.
研究领域:
材料科学
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太阳能
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 14
·4634-4644
·
IF 6.4
Yue Jian,Tianliang Xie,Litao Han,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yuena Meng,Yafang Qi,Sixin Wu
As a promising absorber material for thin film solar cells, the highest reported power conversion efficiency (PCE) of Cu2ZnSn(S,Se)4 (CZTSSe) is still far from the detailed balance limit of efficiency due to the large VOC deficit. Back contact engineering plays an important role in promoting the CZTSSe solar cell towards realizing high PCE. In this study, a MoO3-modified layer with the highest oxidation state 6+ and better thermal stability was in situ introduced by spin-coating Na2S aqueous solution on the Mo electrode. The results demonstrate that the Na2S layer at the rear contact provides more Na to diffuse into the absorber, thus improving the crystallinity of the film and the quality of the p–n heterojunction, and the carrier collection in the neutral region and at the front interface of the devices is enhanced. The formation of the MoO3 layer can also inhibit the decomposition reaction between Mo and CZTSSe, which minimizes the secondary phases and voids, and improves the quality of the back interface. Moreover, the band alignment and interfacial barrier at the back contact were modified by the MoO3 layer, resulting in better carrier collection and the reduction of photogenerated carrier recombination. By optimizing the Na2S (MoO3) layer, the average PCE of the CZTSSe solar cell increased to 12.48% from 10.22% with the large VOC increments of 60 mV and FF increments of 5%, and the best performance was achieved, with an active area efficiency of 12.74% without the anti-reflection coating layer.
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
高影响因子
Small
·
2024
·
IF 13
Han Xu,Rutao Meng,Xuejun Xu,Yue Liu,Yali Sun,Yi Zhang
Alkali metal is the requirement for highly efficient Cu 2 ZnSn(S, Se) 4 (CZTSSe) solar cells, thus it is crucial to additionally incorporate alkali metal into the absorber layer for flexible solar cells. However, the efficiency of flexible CZTSSe devices reported to date, based on the conventional alkali incorporation strategies, still lags behind those made on rigid substrates. One of the main issues is the inability to control the alkali content and distribution in the absorber layer. Here, a facile alkaline incorporation approach is proposed, effectively regulating the content and distribution of alkali metals in the film. Such a method can spontaneously tailor the alkali metal content to a proper level, thus leading to the suppression of non-radiative recombination and a better carrier transport through the enhanced film quality and the optimized band binding structure. Finally, a champion flexible CZTSSe solar cell with an efficiency of 11.88% is achieved, the highest reported efficiency for a CZTSSe solar cell without noble Ag doping. This study affords an innovative spontaneous alkali-doping design for the preparation of high-performance flexible CZTSSe solar cells and provides a deeper insight into the extent of alkali metal doping.
研究领域:
材料科学
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可再生能源
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光伏技术
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DOI
高影响因子
ADVANCED MATERIALS
·
2022
·Vol. 34
·期 27
·2202858
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IF 32.086
Jinlin Wang,Jiazheng Zhou,Xiao Xu,Fanqi Meng,Chunxu Xiang,Licheng Lou,Kang Yin,Biwen Duan,Huijue Wu,Jiangjian Shi,Yanhong Luo,Dongmei Li,Hao Xin,Qingbo Meng
Aiming at a large open-circuit voltage ( V OC ) deficit in Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells, a new and effective strategy to simultaneously regulate the back interface and restrain bulk defects of CZTSSe absorbers is developed by directly introducing a thin GeO 2 layer on Mo substrates. Power conversion efficiency (power-to-efficiency) as high as 13.14% with a V OC of 547 mV is achieved for the champion device, which presents a certified efficiency of 12.8% (aperture area: 0.25667 cm 2 ). Further investigation reveals that Ge bidirectional diffusion simultaneously occurs toward the CZTSSe absorber and MoSe 2 layer at the back interface while being selenized. That is, some Ge element from the GeO 2 diffuses into the CZTSSe absorber layer to afford Ge-doped absorbers, which can significantly reduce the defect density and band tailing, and facilitate quasi-Fermi level split by relatively higher hole concentration. Meanwhile, a small amount of Ge element also participates in the formation of MoSe 2 at the back interface, thus enhancing the work function of MoSe 2 and effectively separating photoinduced carriers. This work highlights the synergistic effect of Ge element toward the bulk absorber and the back interface and also provides an easy-handling way to achieve high-performance CZTSSe solar cells.
研究领域:
材料科学
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光伏技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
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2023
·
IF 13.1
Quanzhen Sun,Yifan Li,Caixia Zhang,Shunli Du,Weihao Xie,Jionghua Wu,Qiao Zheng,Hui Deng,Shuying Cheng
Focusing on the low open circuit voltage ( V OC ) and fill factor (FF) in flexible Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells, indium (In) ions are introduced into the CZTSSe absorbers near Mo foils to modify the back interface and passivate deep level defects in CZTSSe bulk concurrently for improving the performance of flexible device. The results show that In doping effectively inhibits the formation of secondary phase (Cu(S,Se) 2 ) and V Sn defects. Further studies demonstrate that the barrier height at the back interface is decreased and the deep level defects (Cu Sn defects) in CZTSSe bulk are passivated. Moreover, the carrier concentration is increased and the V OC deficit ( V OC,def ) is decreased significantly due to In doping. Finally, the flexible CZTSSe solar cell with 10.01% power conversion efficiency (PCE) has been obtained. The synergistic strategy of interface modification and bulk defects passivation through In incorporation provides a new thought for the fabrication of efficient flexible kesterite-based solar cells.
研究领域:
材料科学
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太阳能
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半导体物理
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·
IF 19
Yafang Qi,Na Wei,Yang Li,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Yuena Meng,Shengjie Yuan,Litao Han,Sixin Wu
The Sn Zn defect passivation and heterojunction interface energetics-modification are crucial for further improvement of open-circuit voltage ( V oc ) and efficiency of Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells. Herein, a simple but effective cation substitution strategy is reported to promote the performance of CZTSSe devices by simultaneously modifying the absorber and heterojunction interface. This is achieved by introducing the organic silicon salt C 8 H 20 O 4 Si into CZTSSe precursor solution as a source of silicon to partially substitute Sn with Si. Systematic studies reveal that there are two mechanisms synergistically contributing to the increase of efficiency: 1) This strategy can passivate the undesired Sn Zn defect in CZTSSe absorber more efficiently, leading to at least one order of magnitude lower Sn Zn defect density and beneficial carrier transport properties; 2) After Si incorporation, the conduction band minimum of the CZTSSe is upshifted, thus enlarging the bandgap, which ultimately optimizes the energy level structure at the CdS/CZTSSe interface and reduces interfacial energy loss by decreasing the carrier transport barrier. Consequently, the CZTSSe device with 7% Si substitution delivers a satisfactory efficiency of 13.02% owing to an increase in V oc . It is hoped the Si substitution strategy reported here can provide inspiration for developing advanced CZTSSe devices with broad application prospects.
研究领域:
材料科学
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能源技术
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Tianliang Xie,Litao Han,Liangli Chu,Mingtao Han,Yue Jian,JinJin Chi,Xinyi Zhong,Tong Liu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yuena Meng,Yafang Qi,Sixin Wu
Insufficient selenization and uneven distribution of elements caused by the poor diffusion and reaction activity of selenium clusters is one of the main issues limiting the efficiency of Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells. Here, this work designs a simple and feasible strategy to improve the activity of selenium (Se) by implementing high-temperature treatment on graphite boxes loaded with Se pellets. The rapid adsorption/desorption characteristics of graphite on active gaseous small-molecule selenium have successfully introduced hyperactive Se 4 , Se 3 , and Se 2 into the selenization process. The results indicate that the adsorbed non-toxic gaseous active Se 3 and Se 4 can quickly and uniformly diffuse into the precursor film at low temperatures, thereby inducing nucleation and grain growth at both surface and back interface simultaneously, which inhibits the upward migration and aggregation of cations, especially Cu, and promotes the homogenization of elements. The overall relatively Cu-poor chemical environment suppresses the formation of Cu Zn defects and [2Cu Zn +Sn Zn ] defect clusters, and also promotes the generation of favorable V Cu . The band tail states and non-radiative recombination are then optimized. Finally, the CZTSSe solar cells achieve a power conversion efficiency (PCE) of 14.5%, with V OC / V OC SQ of 67% being one of the highest in the literature.
研究领域:
材料科学
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太阳能
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半导体物理
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
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2024
·
IF 6
Letu Siqin,Chenjun Yang,Jingyuan Guo,Yutian Wang,Lei Wang,Yuan Li,Yiming Wang,Shuyu Li,Xiangyu Chen,Hongmei Luan,Ruijian Liu,Chengjun Zhu
The high open-circuit voltage deficit (V OC, def ) caused by structural imperfections in the absorber layer and charge loss during carrier transport is a critical barrier affecting the performance of Cu 2 ZnSn(S,Se) 4 (CZTSSe) devices. In this work, Ag was added to the DMF-based Cu + -Sn 4+ system, which significantly improved the crystal morphology and electrical properties of the absorber layer. Additionally, optimizing the selenization process not only reduced surface roughness and eliminated voids at the bottom of the absorber layer but also resulted in the formation of a MoSe 2 back interface layer with a more suitable thickness. These measures collectively enhanced the overall quality of the absorber layer, reducing the formation of deep-level defect clusters and effectively boosting carrier transport efficiency. Consequently, the concentration of bulk and interfacial defects decreased, and the impact of potential barriers on carrier movement was minimized. With these comprehensive improvements, the power conversion efficiency of CZTSSe solar cells increased from 8.48 % to 11.23 %. Our research demonstrates that optimizing the structure of the absorber layer can effectively enhance the performance of CZTSSe solar cells, providing valuable insights for the fabrication of high-efficiency devices in the future.
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
MATERIALS LETTERS
·
2024
·
IF 2.7
Fengxia Yang,Zhilu Zhang,Zhengjun Luo,Xiaofei Dong,Lin Ge,Yan Li
Developing memristors with both light-regulated resistive switching characteristic and optronic synaptic behavior is of great significance for next-generation artificial visual applications. Herein, Cu 2 ZnSn(S,Se) 4 (CZTSSe)-based synaptic memristor is designed and its visible light-modulated resistive switching characteristics, especially the photonic synaptic behaviors, are detailedly investigated. For such Ag/CZTSSe/Mo memristor, not only its Set/Reset switching voltage and R HRS /R LRS ratio can be well regulated by visible light, either the wavelength (470 ∼ 655 nm) or intensity (40 ∼ 110 mW/cm 2 ), but also its photonic synaptic behavior like “learning-forgetting” can be achieved and modulated by light stimuli. The results are of significance for designing artificial photonic synaptic devices in neuromorphic vision application.
研究领域:
神经形态工程
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光电子学
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忆阻器件
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人工突触
✓ 已验证
DOI
高影响因子
Materials
·
2026
·Vol. 19
·期 7
·1337
·
IF 3.7
Xiaogong Lv,Shumin Zhang,Yanchun Yang,Guonan Cui,Wenliang Fan,Xing Yue
Cu 2 ZnSn(S,Se) 4 (CZTSSe) is a candidate thin-film photovoltaic material; however, its performance is restricted by innate defect-induced nonradiative recombination. Low-concentration Ge doping has been identified as an efficient way to mitigate these defects, but the selenization temperature remains an important process parameter that governs the structure and optoelectronic characteristics of CZTSSe absorbers. In the present work, low-concentration Ge-doped Cu 2 ZnSn 0.95 Ge 0.05 S 4 (CZTGS) precursor films were synthesized through a green, n-butylammonium butyrate-based solution approach. The effects of the selenization temperature (530–570 °C) on the microstructure, composition, and photovoltaic performance of Cu 2 ZnSn 0.95 Ge 0.05 (S,Se) 4 (CZTGSSe) films and devices were comprehensively investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometer (EDS), atomic force microscopy (AFM) were performed to comprehensively characterize the synthesized samples, and the results suggested that the selenization temperature dramatically altered the film grain growth, crystallinity, elemental retention and surface roughness. Specifically, the film that underwent selenization at 550 °C presented the best crystallinity, which was accompanied by large-scale even grains, efficient Ge 4+ addition to the kesterite lattice and the lowest surface roughness. These better properties in terms of structure and composition resulted in the lowest carrier transport resistance ( R s = 8.6 Ω∙cm 2 ), improved recombination resistance ( R j = 5.9 kΩ∙cm 2 ), inhibited nonradiative recombination, and prolonged carrier lifetime ( τ EIS = 35.8 μs). Therefore, the resulting CZTGSSe thin-film solar cell had an 8.69% better power conversion efficiency (PCE), while its open-circuit voltage ( V OC ) was 0.42 V, the fill factor (FF) was 55.51%, and the short-circuit current density ( J SC ) was 37.71 mA·cm −2 . Our results elucidate the mechanism by which the selenization temperature regulates low-concentration Ge-doped kesterite devices and provide more insights into the optimization of processes for cost-effective, high-performance, and green thin-film solar cells.
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Mengping He,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Yuena Meng,Sixin Wu
The earth-abundant Cu2ZnSnS4 (CZTS) quantum dots (QDs) have emerged as one potential substitute to toxic cadmium or rare indium QDs, but their application in quantum dot-sensitized solar cells (QDSSCs) is still limited by the improper particle size and the rigorous synthesis and ligand exchange conditions. Herein, we developed a one-pot hot injection method by using Tri-n-octylphosphine oxide (TOPO) as the solvent and oleylamine as the capping agent to synthesize Cu2ZnSn(S,Se)4 (CZTSSe) QDs with adjustable size and narrow size distribution. The key feature of this approach is that we can take advantage of the high-temperature nucleation, low-temperature growth, and strong reducibility of NaHB4 to prepare small-sized CZTSSe QDs without using 1-dodecanethiol (DDT) and to extend the light harvesting range through Se incorporation. After Se incorporation, it turns out that the conduction band (CB) level of CZTSSe QDs decreases, implying that the injection driving force of the electron to the CB of TiO2 films becomes weaker and a larger recombination would be induced at the TiO2/QDs/electrolyte interface. Benefiting from the broadened optoelectronic response range, the induced higher Jsc (16.80 vs 14.13 mA/cm2) finally leads to the increase of the conversion efficiency of CZTSSe QDSSC from 3.17% to 3.54% without further modification. Despite the fact that the efficiency is still far behind those of literature reported values through use of other chalcogenide sensitizers, this DDT-free approach solves the main hindrance for the application of CZTSSe QDs in QDSSCs and holds a more convenient way for ligand exchange, light absorption improvement, and particle size control.
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
Advanced Science
·
2026
·
IF 14.1
Yixiong Ji,Wentong Yang,Di Yan,Wei Luo,Jialu Li,Shi Tang,Jintao Fu,James Bullock,Mei Gao,Xin Li,Zhancheng Li,Jun Yang,Zhenghong Xiong,Yang Peng,Pengjun Zhao,Xingzhan Wei,Haofei Shi,Paul Mulvaney,Fangyang Liu
Flexible kesterite Cu 2 ZnSn (S,Se) (CZTSSe) solar cells on metal foils are attractive for lightweight and conformable photovoltaic applications, yet their efficiencies remain significantly lower than those of rigid devices due to severe foil‐induced rear‐interface losses during high‐temperature chalcogenization. These effects include uncontrolled Mo(S,Se) formation, interfacial instability, and the emergence of blocking back‐contact barriers that hinder efficient carrier extraction. Here, we introduce a single‐crystal graphene interlayer to engineer the Mo foil/CZTSSe interface. The atomically thin graphene layer decouples absorber growth from the mechanically and chemically non‐ideal foil surface, suppressing detrimental interfacial reactions and stabilizing the rear interface. As a result, carrier extraction is enhanced, and the back‐contact barrier is reduced toward quasi‐ohmic behavior. Flexible CZTSSe solar cells with graphene‐engineered interfaces achieve a champion efficiency of 11.6% with simultaneous improvements in V OC , J SC , and fill factor. These results highlight rear‐interface stabilization as a key strategy for improving flexible kesterite photovoltaics on metal substrates. An atomically thin graphene interlayer stabilizes the rear interface of flexible CZTSSe solar cells by regulating interfacial stress, suppressing detrimental interfacial reactions, and reducing the back‐contact barrier. This strategy simultaneously improves photovoltaic performance and mechanical durability.
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DOI
PubMed
高影响因子
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