Review
Chemistry, Physical
Sunil Suresh, Alexander R. Uhl
Summary: Photovoltaic technologies provide a sustainable solution to increasing energy demands, with chalcopyrite thin-film solar cells exhibiting high efficiency but typically fabricated using vacuum deposition methods. Research is shifting towards solution processing techniques to improve material usage, increase throughput, and lower commercialization barriers, but performance of current devices falls short of vacuum-processed counterparts.
ADVANCED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Gi Soon Park, SeungJe Lee, Da-Seul Kim, Sang Yeun Park, Jai Hyun Koh, Da Hye Won, Phillip Lee, Young Rag Do, Byoung Koun Min
Summary: Ultrathin solar cells (UTSCs) have attracted attention due to their low-cost production and potential applications. To achieve high efficiency, passivation of the rear-interface is crucial, especially for thinner absorbers. This study introduces amorphous TiO2 layers as passivating contacts for solution-processed UTSCs, which not only passivate defective rear-interfaces but also provide excellent electrical conduction. The amorphous nature of TiO2 layers enables desirable ohmic conduction over the entire area without any contact openings.
ADVANCED ENERGY MATERIALS
(2023)
Article
Energy & Fuels
Bowen Liu, Xinan Shi, Wei Shao, Jiaxin Gao, Chenxi Zhao, Fuyan Chen, Dongdong Shen, Bingsuo Zou, Daocheng Pan
Summary: A novel and green ionic liquid-assisted ink is developed for the fabrication of highly efficient CIGSSe solar cells by inkjet printing. Compared to the conventional vacuum-based deposition and spin-coating solution methods, inkjet printing technology can remarkably improve the material utilization of copper indium gallium sulfur selenium (CIGS) and achieve a flat and continuous deposition of CIGS thin film. The inkjet-printed CIGSSe solar cells show an encouraging power conversion efficiency of 15.22%.
Article
Nanoscience & Nanotechnology
Van Ben Chu, Daniel Siopa, Alice Debot, Damilola Adeleye, Mohit Sood, Alberto Lomuscio, Michele Melchiorre, Jerome Guillot, Nathalie Valle, Brahime El Adib, Jonathan Rommelfangen, Phillip J. Dale
Summary: Chemical bath methods for growing thin film semiconductors produce a lot of waste solvent and chemicals. This study successfully replaced the toxic chemical bath deposited CdS buffer layer with a benign inkjet-printed and annealed Zn(O,S) layer, greatly reducing solvent and chemical usage. The wetting and final performance of the Zn(O,S) layer on CIGS can be controlled by various factors, with the best device efficiency reaching 13.5% through optimization.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Shaohong Yang, Wencai Zhou, Jingjing Qu, Linrui Zhang, Xiaoyu Lv, Zilong Zheng, Xiaoqing Chen, Hui Yan, Ming Zhao, Daming Zhuang
Summary: Cu(In,Ga)(Se,S)(2) has distinct advantages as a photovoltaic material, allowing independent tuning of its conduction and valence bands, as well as its composition distribution. Through calculations and simulations, we achieved high-efficiency Cu(In,Ga)(Se,S)(2) solar cells with an efficiency of 23.29%, providing an understanding of tunable engineered band energy research.
Article
Electrochemistry
Behzad Mahmoudi, Francesco Caddeo, Titus Lindenberg, Thomas Schneider, Torsten Hoelscher, Roland Scheer, A. Wouter Maijenburg
Summary: In this study, polycrystalline Cu-Ga-Se films with different compositions were prepared to investigate the effect of the Cu/Ga ratio on crystal structure, morphology, and PEC performance. Remarkable saturated photocurrent densities were observed for films with Cu/Ga ratios of 0.85 and 0.33, covering a significant portion of the maximum theoretical photocurrents for materials with band gaps of 1.68 eV and 1.85 eV, respectively. Additionally, electrochemical impedance spectroscopy (EIS) confirmed the consistency between the difference in onset potential and flat-band potential between the two films.
ELECTROCHIMICA ACTA
(2021)
Article
Chemistry, Physical
Oana Cojocaru-Miredin, Elaheh Ghorbani, Mohit Raghuwanshi, Xiaowei Jin, Dipak Pandav, Jens Keutgen, Reinhard Schneider, Dagmar Gerthsen, Karsten Albe, Roland Scheer
Summary: Research has shown that intense sulphurization processes in Cu(In,Ga)Se-2 thin-film solar cells, combined with Ga-grading, can lead to improved electrical properties of the buffer/absorber heterojunction by reducing p-doping and altering the band diagram. This process results in the formation of a S-rich compound at the absorber surface, ultimately offering new possibilities for synthesizing high-performance Cu(In,Ga)(Se,S)(2) solar cells.
Article
Energy & Fuels
Ke Cheng, Xingfen Shen, Jingling Liu, Xinsheng Liu, Zuliang Du
Summary: A sequential route for low-cost fabrication of high quality Ag-alloyed CIGS absorbers is reported, where Ag-alloying is introduced into the CuInGa precursor to widen the band gap and improve the crystallinity of the ACIGS absorbers. Different Ag thin layer incorporation locations are schemed for deep understanding the band gap energy and crystallinity regulation mechanism of Ag alloying, leading to a notable improvement in Voc. Finally, the ACIGS absorbers are sulfurized to achieve a highest power conversion efficiency of 13.01%.
Article
Chemistry, Physical
Guangxing Liang, Zhidong Li, Muhammad Ishaq, Zhuanghao Zheng, Zhenghua Su, Hongli Ma, Xianghua Zhang, Ping Fan, Shuo Chen
Summary: This study addresses the main issues of Cu2ZnSn(S,Se)(4) (CZTSSe) in solar energy conversion devices, including severe charge carrier recombination and sluggish charge separation efficiency, by fabricating a planar-type Mo/CZTSSe/CdS/TiO2/Pt photocathode. The high-quality CZTSSe film and favorable energy band alignment of CZTSSe/CdS heterojunction significantly enhance the device performance, achieving a remarkable photocurrent density and solar-to-hydrogen conversion efficiency.
ADVANCED ENERGY MATERIALS
(2023)
Review
Chemistry, Physical
Sunil Suresh, David J. Rokke, Amandine A. Drew, Essam Alruqobah, Rakesh Agrawal, Alexander R. Uhl
Summary: This article reviews the extrinsic doping concepts for CIGSSe-type absorbers fabricated by ink-based deposition routes, compares the performance of select high-efficiency ink-based devices, and offers an outlook for future process development. It suggests that the mechanisms of ink-based absorbers are fundamentally different from vacuum-based processes and require further investigation.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Weimin Li, Qiuming Song, Chenchen Zhao, Tongqing Qi, Chen Zhang, Wei Wang, Chuanzeng Gao, Xue Zheng, De Ning, Ming Ma, Jun Zhang, Ye Feng, Ming Chen, Wenjie Li, Chunlei Yang
Summary: This study proposes an effective method to improve the V-oc of chalcopyrite solar cells by using a simultaneous rapid thermal selenization and sulfurization process (RTP). By optimizing the H2S gas concentration and Se capping layer thickness, high-efficiency CIGSSe solar cells with an efficiency above 17% have been successfully achieved, reducing the high-temperature process duration to less than 5 minutes and eliminating the need for toxic and expensive H2Se.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Multidisciplinary Sciences
Bo Wu, Tuo Wang, Bin Liu, Huimin Li, Yunlong Wang, Shujie Wang, Lili Zhang, Shaokun Jiang, Chunlei Pei, Jinlong Gong
Summary: This paper presents the design and fabrication of a discontinuous hybrid organic protective layer with controllable surface wettability for Si-based photocathodes. By inducing the formation of thin gas layers at the discontinuous pores, the electrolyte is isolated from the Si substrate, while Pt co-catalyst can still contact the electrolyte for water splitting. The optimized photocathode achieves stable solar water splitting for over 110 hours.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Jakapan Chantana, Yu Kawano, Abdurashid Mavlonov, Takashi Minemoto
Summary: Flexible, lightweight, and Cd-free CIGSSe solar cells on stainless steel substrates were fabricated using special buffer and TCO layers. By optimizing the material composition, the photovoltaic performances of the devices can be improved, and carrier recombination can be effectively reduced.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Jakapan Chantana, Yu Kawano, Takahito Nishimura, Abdurashid Mavlonov, Takashi Minemoto
Summary: This study investigates the structure and sample position effects on the performance of flexible, Cd-free, and all-dry process Cu(In,Ga)(S,Se)₂ (CIGSSe) solar cells on stainless steel substrates. The results show that the sample position plays a vital role in improving the cell performance, with a deviation from material targets leading to enhanced photovoltaic efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Qianqian Chang, Shengjie Yuan, Junjie Fu, Qianqian Gao, Yunhai Zhao, Zhen Xu, Dongxing Kou, Zhengji Zhou, Wenhui Zhou, Sixin Wu
Summary: Indium doping of cadmium sulfide (CdS) by chemical bath deposition (CBD) is an efficient strategy to enhance the efficiency of CIGSSe. However, the low solubility of In2S3 limits the In doping contents and band energy-level regulation for CdS using traditional CBD process. In this study, a novel CBD method is used to prepare indium-doped CdS (In:CdS) buffer by slowly adding the indium source in the growing solution. This reduces the In ion concentration during real-time deposition and leads to the formation of compact and uniform In:CdS with higher indium doping content. In:CdS improves the heterojunction quality of CIGSSe by elevating the CdS conduction band edge, achieving a more favorable band alignment and enhancing carrier transport efficiency while reducing interface defect density. The solution-processed CIGSSe device with In:CdS as a buffer exhibits a high efficiency of 16.4%, characterized by a high V-OC of 670 mV and an FF of 75.3%.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Gi Soon Park, SeungJe Lee, Da-Seul Kim, Sang Yeun Park, Jai Hyun Koh, Da Hye Won, Phillip Lee, Young Rag Do, Byoung Koun Min
Summary: Ultrathin solar cells (UTSCs) have attracted attention due to their low-cost production and potential applications. To achieve high efficiency, passivation of the rear-interface is crucial, especially for thinner absorbers. This study introduces amorphous TiO2 layers as passivating contacts for solution-processed UTSCs, which not only passivate defective rear-interfaces but also provide excellent electrical conduction. The amorphous nature of TiO2 layers enables desirable ohmic conduction over the entire area without any contact openings.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Songwoung Hong, Woo Lee, Yun Jeong Hwang, Seungwoo Song, Seungwook Choi, Hyun Rhu, Jeong Hyun Shim, Ansoon Kim
Summary: To prevent photocorrosion, a thick TiO2 film with electrical leakage was deposited onto an n-Si photoanode surface. Modulating the defect density of the TiOx film enhanced hole transport and water-splitting activity. The photoanode with optimal defect density retained 85% of the initial current density after 100 hours.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Engineering, Environmental
Yong Jae Cho, Chihyung Lee, Hyeong Cheol Kang, Byunghoon Kim, Gyu-Hee Kim, Gumin Kang, Junyeong Ryu, Kicheon Yoo, Gi Soon Park, Kyu-Tae Lee, Byoung Koun Min, Jae-Joon Lee, Doo-Hyun Ko
Summary: In this study, a highly-efficient quantum dot hierarchical film was developed to enhance the performance of photovoltaic devices. By integrating quantum dots with micro/nano hierarchical structures, the film achieved low reflectance for incident light and high reflectance for escape light, resulting in increased absorption of photovoltaics at wide incident angles. The hierarchical structure also restricted the outward release of converted quantum dot photoluminescence, ensuring higher availability of down-shifted photons to photovoltaics. Experimental results showed that applying this film on both sides of bifacial semi-transparent dye-sensitized solar cells improved the short-circuit current density by up to 25.97% under AM 1.5G illumination. This study provides a new perspective on advanced spectral converting layers and practical viability for various optoelectronic devices.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Chemistry, Physical
Dongjin Kim, Younghyun Chae, Ung Lee, Woong Kim, Da Hye Won
Summary: Electrochemical CO2 reduction (eCO2R) is a promising strategy for reducing atmospheric CO2, and recent developments in membrane electrode assembly (MEA) have greatly improved its performance. This review provides an overview of the studies on MEA development for CO production, including catalysts and their modification strategies, cell operating conditions, and remaining challenges.
CURRENT OPINION IN ELECTROCHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Si Young Lee, Jimin Kim, Gwangsu Bak, Eunchong Lee, Dayeon Kim, Suhwan Yoo, Jiwon Kim, Hyewon Yun, Yun Jeong Hwang
Summary: In this study, the effect of cations on *CO intermediates on the Cu(OH)(2)-derived catalyst was directly observed in real-time. Different sensitivities to the cation-induced field were found for two *CO intermediates, with *COHFB being the dominant active species. Furthermore, a decrease in the hydrated cation size promoted C-C coupling and suppressed C1 product formation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Jiwon Kim, Jae Hyung Kim, Cheoulwoo Oh, Hyewon Yun, Eunchong Lee, Hyung-Suk Oh, Jong Hyeok Park, Yun Jeong Hwang
Summary: An electro-assisted approach using acid-treated carbon electrocatalyst and in-situ cathodically generated reactive oxygen species is proposed for the partial oxidation of methane at ambient temperature and pressure. Reactive oxygen species activate methane and methanol, leading to selective methane partial oxidation. This study presents a method for the electrochemically assisted partial oxidation of methane to produce liquid oxygenate, HCOOH, selectively.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Hyewon Yun, Woong Choi, Dongwoo Shin, Hyung-Suk Oh, Yun Jeong Hwang
Summary: Tailoring catalyst performance in zero-gap MEA electrolyzers is crucial. However, few studies have directly focused on MEA systems combined with operando techniques. This study demonstrates improved catalytic performance of AuAg bimetallic catalyst by adjusting the atomic arrangement and extrinsic properties. The catalyst achieved high CO selectivity and CO partial current density and mass activity through proper adjustment of the carbon support.
Article
Chemistry, Physical
Chaeeun Lim, Dongkyu Kim, Mingyun Kim, Hyeju Yun, Dongwoo Shin, Yun Jeong Hwang, Hyeyoung Shin, Kijung Yong
Summary: In this study, a sulfur-derived solid-electrolyte interface (SEI) was introduced to enhance the stability and energy efficiency of Li-mediated nitrogen reduction reaction (Li-NRR). By engineering the physical structure of SEI, the ion conductivity and electron insulation properties were improved, leading to better Li plating uniformity and reduced electrolyte decomposition. The introduction of sulfur maintained a steady cell potential over 20 h, significantly enhancing energy efficiency.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Eunchong Lee, Jae Hyung Kim, Juhyung Choi, Yewon Hong, Dongwoo Shin, Hyewon Yun, Jimin Kim, Gwangsu Bak, Seongin Hong, Yun Jeong Hwang
Summary: In this study, the electrochemical oxidation reaction of furfural to produce maleic acid was investigated. It was found that doping lead oxide with bismuth effectively tuned the activity for the oxidation reaction and increased the selectivity for maleic acid production. The addition of bismuth suppressed the overoxidation of maleic acid to carbon dioxide. These results suggest that mixed metal oxides can be utilized to adjust the oxidation activity and enhance selective electrosynthesis from biomass conversion.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Younghyun Chae, Kyeongsu Kim, Hyewon Yun, Dongjin Kim, Wonsang Jung, Yun Jeong Hwang, Ung Lee, Dong Ki Lee, Byoung Koun Min, Woong Choi, Da Hye Won
Summary: The study investigates the impact of substrate on the performance of the electrochemical CO2 reduction reaction. It reveals that a porous carbon paper substrate facilitates CO2 supply and diffusion, leading to higher efficiency in CO2RR.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Guocheng Deng, Hyewon Yun, Megalamane S. Bootharaju, Fang Sun, Kangjae Lee, Xiaolin Liu, Seungwoo Yoo, Qing Tang, Yun Jeong Hwang, Taeghwan Hyeon
Summary: Studying the atomistic synergistic effects of nanoalloys on the electrocatalytic CO2 reduction reaction is crucial, but determining the atomic-level structure of appropriate analogues is challenging. In this study, a one-pot synthesis and structure characterization of an AuCu nanoalloy cluster catalyst were reported, which provided insights into the atomistic synergistic effects of Au and Cu on the reaction. The results showed that the AuCu nanoalloy exhibited excellent catalytic performance in the CO2 reduction reaction, with higher CO Faradaic efficiency and CO partial current density compared to the closest monometal analogue.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Ji Hwan Song, Seohyeon Ka, Chulwan Lim, Man Ho Han, Dong Ki Lee, Hyung-Suk Oh, Woong Hee Lee
Summary: We have revealed the reaction environment of the anode during the CO2 reduction reaction, finding that the pH fluctuations caused by nonuniform ion and water distribution result in rapid phase transition and severe degradation of nickel-based electrodes in MEA.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Suhyun Lee, Woong Choi, Jae Hyung Kim, Sohyeon Park, Yun Jeong Hwang, Jonggeol Na
Summary: This study evaluates the economic and environmental potential of direct electrochemical conversion of captured CO2 technology through techno-economic analysis and life cycle assessment. The results indicate that the technology has good economic potential if developed to the same level as the conventional CO2 reduction reaction process. Moreover, the environmental impact of the technology is positive, especially when using renewable electricity.
