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23. Synergistic Carbonyl and Cyano Passivation for Efficient Blade-Coated Perovskite Solar Cells

Author

Li, Xinxin, Zhou, Long, Chen, Qianyu, Zhang, Yunlong, Feng, Xinyuan, Du, Yuanbo, Chen, Dazheng, Zhu, Weidong, Xi, He, Zhang, Jincheng, Zhang, Chunfu, and Hao, Yue

Abstract

Homogeneous and defect-minimized perovskite films are critical for efficient perovskite solar cells (PSCs). Herein, we introduce a small molecule with electron-rich carbonyl and cyano groups in the perovskite films to regulate the crystallization process and passivate defects. The electron-rich carbonyl and cyano groups of the FDP molecules could coordinate with Pb $^{{2}+}$ dangling bonds and reduce the density of VPb. The synergistic effect of crystallization modulation and defect passivation could significantly improve film quality and suppress carrier nonradiative recombination. As a result, the champion devices realize an increased efficiency of 23.39% for small areas (0.08 cm $^{{2}}\text {)}$ and a high efficiency of 20.69% for larger areas (1 cm $^{{2}}\text {)}$ . The inverted perovskite modules with an aperture area of 45 cm2 obtain a champion efficiency of 20.38%, indicating a teeny efficiency loss of 1.5% from 1 to 45 cm2. These findings provide an innovative avenue to achieve high-efficiency perovskite modules and facilitate the commercialization of large-area PSCs.

Published
2024
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24. Recent progress of Ga2O3materials and devices based on the low-cost, vacuum-free Mist-CVD epitaxial growth method

Author

Zhang, Zeyulin, Yan, Pengru, Song, Qingwen, Chen, Haifeng, Zhang, Wentao, Yuan, Hao, Du, Fengyu, Liu, Dinghe, Chen, Dazheng, and Zhang, Yuming

Abstract

Compared with silicon, gallium nitride, silicon carbide, and other traditional semiconductors, gallium oxide (Ga2O3) who possesses, an ultrawide bandgap of approximately 5.0 eV and a higher breakdown field strength of approximately 8 MV/cm has attracted increasing attention from researchers, especially for the potential application in power devices. Moreover, Ga2O3material has natural ultraviolet detection ability for photodetectors due to its ultrawide bandgap. These future commercial applications put forward an urgent require for high-quality epitaxial Ga2O3material in an efficient growth method at a lower cost. Although there are some conventional methods for single crystal Ga2O3film epitaxial growth such as MBE and MOCVD, these methods always need a vacuum growth environment and expensive equipment. As a fast-growing method, Mist-CVD gives the growth of Ga2O3in a vacuum-free, process-simple, and low-cost method, which will greatly reduce the cost and facilitate the development of Ga2O3. This review has summarizes the Mist-CVD epitaxy growth mechanism of Ga2O3, recent progress in the Ga2O3film epitaxial growth, and various device properties based on the Mist-CVD method. Our work aims to provide help for the development of Ga2O3material growth and device applications.

Published
2024
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33. Performance Enhancement of NiOx/β-Ga₂O₃ Heterojunction Diodes by Synergistic Interface Engineering

Author

Liu, Dinghe, Zhang, Zeyulin, Chen, Hao, Tian, Xusheng, Wang, Yao, Yan, Yiru, Zeng, Liru, Liu, Xinke, Chen, Dazheng, Feng, Qian, Zhou, Hong, Liu, Zhihong, Zhang, Jincheng, Zhang, Chunfu, and Hao, Yue

Abstract

In this work, we report on achieving enhanced performance NiOx/beta gallium oxide ( $\beta $ -Ga2O3) heterojunction p-n diodes (HJDs) through synergistic interface engineering (SIE), which can greatly improve the electrical characteristics and interface characteristics of HJDs. It is shown that the NiOx surface undergoes morphological improvement and hole concentration enhancement after the UV/ozone treatment (UVO). Owing to the improved interfacial properties of Ni/NiOx, the forward conduction current of NiOx/ $\beta $ -Ga2O3 HJD has significantly increased. Furthermore, the HJD performance can be improved by SIE with UVO and postannealing, especially for the reverse breakdown characteristics. Finally, a high-performance HJD without any terminal structure is obtained, which exhibits a low specific on-resistance of 2.47 m $\Omega \cdot $ cm2 and a high breakdown voltage of 1355 V, yielding a high Baliga’s figure of merit (BFOM) of 0.743 GW/cm2, which is a 219.17% enhancement in performance compared to untreated device. This work offers a practical and effective strategy for developing advanced Ga2O3 devices with exceptional performance metrics, paving the way for future technological breakthroughs.

Published
2024
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36. MXene‐Interconnected Two‐Terminal, Mechanically‐Stacked Perovskite/Silicon Tandem Solar Cell with High Efficiency.

Author

Han, Tianjiao, Zhu, Weidong, Wang, Tianran, Yang, Mei, Zhou, Yuanbo, Xi, He, Zhong, Peng, Chen, Dazheng, Zhang, Jincheng, Zhang, Chunfu, and Hao, Yue

Subjects
SILICON solar cells, PHOTOVOLTAIC power systems, SOLAR cell efficiency, SOLAR cells, PEROVSKITE, LIGHT transmission, CRYSTAL grain boundaries
Abstract

Two‐terminal, mechanically‐stacked perovskite/silicon tandem solar cells offer a feasible way to achieve power conversion efficiencies (PCEs) of over 35%, provided that the state‐of‐the‐art industrial silicon solar cells and perovskite solar cells (PSCs) are fully compatible with one another. Herein, two‐terminal, mechanically‐stacked perovskite/silicon tandem solar cells are developed by mechanically interconnecting semitransparent PSCs and TOPCon solar cells with a MXene interlayer. The semitransparent PSCs are made from wide‐bandgap perovskite Cs0.15FA0.65MA0.20Pb(I0.80Br0.20)3 films. Furthermore, the co‐additives KPF6 and CH3NH3Cl(MACl) are employed to reduce grain boundaries and intragranular defects in the perovskite, boosting the PCE of the semitransparent PSCs to a record‐high value of 20.96% under reverse scan (RS) through a reduction in non‐radiative recombination probability. These optimized semitransparent PSCs are then employed in MXene‐interconnected two‐terminal, mechanically‐stacked tandem solar cells. The enhanced interfacial carrier transportation, with minimal influence on light transmission, imparted by the MXene flakes allows the tandem solar cells to achieve a stabilized PCE of 29.65%. The tandem cells also exhibit acceptable operational stability and are able to retain ≈93% and 92% of their initial PCEs after 120 min of continuous illumination or storage in ambient air for 1000 h, respectively. [ABSTRACT FROM AUTHOR]

Published
2024
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43. Accelerated Sequential Deposition Reaction via Crystal Orientation Engineering for Low‐Temperature, High‐Efficiency Carbon‐Electrode CsPbBr3 Solar Cells.

Author

Zhang, Zeyang, Zhu, Weidong, Han, Tianjiao, Wang, Tianran, Chai, Wenming, Zhu, Jiaduo, Xi, He, Chen, Dazheng, Lu, Gang, Dong, Peng, Zhang, Jincheng, Zhang, Chunfu, and Hao, Yue

Subjects
CRYSTAL orientation, SOLAR cells, VIDEO on demand, ACTIVATION energy, ENGINEERING, GLASS-ceramics
Abstract

Low‐temperature, ambient processing of high‐quality CsPbBr3 films is demanded for scalable production of efficient, low‐cost carbon‐electrode perovskite solar cells (PSCs). Herein, we demonstrate a crystal orientation engineering strategy of PbBr2 precursor film to accelerate its reaction with CsBr precursor during two‐step sequential deposition of CsPbBr3 films. Such a novel strategy is proceeded by adding CsBr species into PbBr2 precursor, which can tailor the preferred crystal orientation of PbBr2 film from [020] into [031], with CsBr additive staying in the film as CsPb2Br5 phase. Theoretical calculations show that the reaction energy barrier of (031) planes of PbBr2 with CsBr is lower about 2.28 eV than that of (020) planes. Therefore, CsPbBr3 films with full coverage, high purity, high crystallinity, micro‐sized grains can be obtained at a low temperature of 150 °C. Carbon‐electrode PSCs with these desired CsPbBr3 films yield the record‐high efficiency of 10.27% coupled with excellent operation stability. Meanwhile, the 1 cm2 area one with the superior efficiency of 8.00% as well as the flexible one with the champion efficiency of 8.27% and excellent mechanical bending characteristics are also achieved. [ABSTRACT FROM AUTHOR]

Published
2024
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47. High-quality crystalline NiO/β-Ga2O3p–n heterojunctions grown by the low-cost and vacuum-free mist-CVD for device applications

Author

Zhang, Zeyulin, Song, Qingwen, Liu, Dinghe, Yan, Yiru, Chen, Hao, Mu, Changgen, Chen, Dazheng, Feng, Qian, Zhang, Jincheng, Zhang, Yuming, Hao, Yue, and Zhang, Chunfu

Abstract

Gallium oxide (Ga2O3) p–n heterojunctions play an important role in addressing the difficulties in Ga2O3p-type doping. Therefore, an efficient and economical fabrication method needs to be established to create single-crystal Ga2O3heterojunctions for device applications. In this work, we successfully achieved epitaxial growth of single-crystal nickel oxide (NiO) and β-Ga2O3heterojunctions based on the low-cost and vacuum-free mist chemical-vapor deposition. The full width at half maximum of the X-ray diffraction rocking curves of NiO (111) and β-Ga2O3(−201) reached 0.077° and 0.807°, respectively. The energy band between NiO and β-Ga2O3has a Type II heterojunction. Finally, we prepared a quasi-vertical diode based on the NiO/β-Ga2O3heterojunction, which exhibits obvious rectification characteristics of the p–n junction and provides a reverse breakdown voltage of 117 V. This work proposes a low-cost fabrication method for β-Ga2O3p–n heterojunctions.

Published
2024
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50. Boosting the Performance of β‐Ga2O3 Solar‐Blind Deep UV Photodetectors by Balancing the Photocurrent and Dark Current via the IZO Interlayer.

Author

Zhang, Zeyulin, Song, Qingwen, Yuan, Hao, Du, Fengyu, Ma, Runping, Liu, Dinghe, Zhang, Yuming, Yan, Pengru, Chen, Dazheng, Zhang, Chunfu, and Hao, Yue

Subjects
PHOTODETECTORS, ANNEALING of metals, CHEMICAL vapor deposition, INDIUM oxide, ZINC oxide, PHOTOCATHODES, GALLIUM
Abstract

There is a tradeoff between the high photocurrent and the low dark current for the gallium oxide (Ga2O3) metal–semiconductor–metal photodetectors (PDs). Achieving a balance between the photocurrent and dark current is crucial to the final device's performance. Herein, indium zinc oxide (IZO) is introduced between the Ga2O3 and the metal contact for the first time. By adjusting the IZO interlayer thickness and the annealing temperature, the barrier height between Ga2O3 and the metal contact can be well controlled. In detail, the β‐Ga2O3 film is epitaxially grown by mist chemical vapor deposition, and the different thicknesses of IZO are deposited under Ti/Au electrode. The devices with 10 nm IZO interlayer and 300 °C annealing temperatures have an obvious device performance improvement, which has achieved responsivity (R) of 508 A W−1, a high peak detectivity (D*) of 2.65 × 1015 Jones, and a raised‐up relaxation time of 0.25 s (fast) and 1.22 s (slow). Compared with the device without IZO, the performances get obviously enhanced. Hence, the work hopes to promote the development of the β‐Ga2O3 solar‐blind deep UV PDs. [ABSTRACT FROM AUTHOR]

Published
2023
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