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Xinbo Yang

Bio: Xinbo Yang is an academic researcher from Soochow University (Suzhou). The author has contributed to research in topics: Silicon & Crystalline silicon. The author has an hindex of 19, co-authored 75 publications receiving 1769 citations. Previous affiliations of Xinbo Yang include Chinese Academy of Sciences & King Abdullah University of Science and Technology.


Papers
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Journal ArticleDOI
TL;DR: In this article, the perovskite cell devices were designed and analyzed with the support of the Australian Government through the Australian Renewable Energy Agency (ARENA) and the Australian Research Council.
Abstract: This work was supported by the Australian Government through the Australian Renewable Energy Agency (ARENA) and the Australian Research Council. Responsibility for the views, information or advice expressed herein is not accepted by the Australian Government. J.P. acknowledges the funding support from Australian Nanotechnology Network (ANN) and Department of Innovation, Industry, Science and Research (DIISR). The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). The authors thank Xavier Pita, scientific illustrator at King Abdullah University of Science and Technology (KAUST), for producing Figure 1a in this paper. J.P. conceived the idea, designed the overall experiments, and led the project. J.P., T.D., H.S., and Y.W. prepared and characterized the perovskite cell devices. J.I.K. and E.U. performed the TA and TRPL measurements and data analysis. F.L. supervised the TA and TRPL measurements and analysis. W.L., X.Y., and J. P. conducted the FTIR measurements and analysis. W.L. performed the DFT calculation. T.D., H.S., and Y.W. conducted the PL imaging measurements. H.D. conducted the XRD and SEM measurements. K.W. conducted the NMR measurements and analysis. E.A. conducted the EQE measurements. J.P., J.I.K., K.J.W., K.R.C., F.L., S.D.W., and T.P.W. contributed to the results analysis and interpretation. T.P.W. and S.D.W. supervised the project. J.P. wrote the manuscript. All authors contributed to the discussion of the results and revision of the manuscript.

331 citations

Journal ArticleDOI
TL;DR: De Wolf et al. as mentioned in this paper reviewed the fundamental physical processes governing contact formation in crystalline silicon (c-Si) and identified the role passivating contacts play in increasing c-Si solar cell efficiencies beyond the limitations imposed by heavy doping and direct metallization.
Abstract: The global photovoltaic (PV) market is dominated by crystalline silicon (c-Si) based technologies with heavily doped, directly metallized contacts. Recombination of photo-generated electrons and holes at the contact regions is increasingly constraining the power conversion efficiencies of these devices as other performance-limiting energy losses are overcome. To move forward, c-Si PV technologies must implement alternative contacting approaches. Passivating contacts, which incorporate thin films within the contact structure that simultaneously supress recombination and promote charge-carrier selectivity, are a promising next step for the mainstream c-Si PV industry. In this work, we review the fundamental physical processes governing contact formation in c-Si. In doing so we identify the role passivating contacts play in increasing c-Si solar cell efficiencies beyond the limitations imposed by heavy doping and direct metallization. Strategies towards the implementation of passivating contacts in industrial environments are discussed. The development of passivating contacts holds great potential for enhancing the power conversion efficiency of silicon photovoltaics. Here, De Wolf et al. review recent advances in material design and device architecture, and discuss technical challenges to industrial fabrication.

326 citations

Journal ArticleDOI
TL;DR: Thin TiO2 films are demonstrated to be an excellent electron-selective contact for crystalline silicon solar cells featuring a full-areaTiO2 -based electron- selective contact.
Abstract: Thin TiO2 films are demonstrated to be an excellent electron-selective contact for crystalline silicon solar cells. An efficiency of 21.6% is achieved for crystalline silicon solar cells featuring a full-area TiO2 -based electron-selective contact.

286 citations

Journal ArticleDOI
TL;DR: In this paper, the electron-selective contact characteristics of ultrathin TiOx films deposited by atomic layer deposition on silicon are investigated via simultaneous consideration of the surface passivation quality and the contact resistivity.

161 citations

Journal ArticleDOI
TL;DR: In this article, the authors report further progress of TiO2 contacts for silicon solar cells and present an assessment of their industrial feasibility with improved TiOO2 contact quality and cell processing, a remarkable efficiency of 221% has been achieved using an n-type silicon solar cell featuring a full-area titanium dioxide contact.
Abstract: Dopant-free, carrier-selective contacts (CSCs) on high efficiency silicon solar cells combine ease of deposition with potential optical benefits Electron-selective titanium dioxide (TiO2) contacts, one of the most promising dopant-free CSC technologies, have been successfully implemented into silicon solar cells with an efficiency over 21% Here, we report further progress of TiO2 contacts for silicon solar cells and present an assessment of their industrial feasibility With improved TiO2 contact quality and cell processing, a remarkable efficiency of 221% has been achieved using an n-type silicon solar cell featuring a full-area TiO2 contact Next, we demonstrate the compatibility of TiO2 contacts with an industrial contact-firing process, its low performance sensitivity to the wafer resistivity, its applicability to ultrathin substrates as well as its long-term stability Our findings underscore the great appeal of TiO2 contacts for industrial implementation with their combination of high efficiency with robust fabrication at low cost Copyright © 2017 John Wiley & Sons, Ltd

128 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors review the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective and give an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrierselective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic-inorganic perovskite materials.
Abstract: With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses key factors responsible for the success of the classic dopant-diffused silicon homojunction solar cell. Next it analyzes two archetypal high-efficiency device architectures – the interdigitated back-contact silicon cell and the silicon heterojunction cell – both of which have demonstrated power conversion efficiencies greater than 25%. Last, it gives an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrier-selective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic–inorganic perovskite materials.

751 citations

Journal ArticleDOI
TL;DR: In this paper, the predominant pathways that contribute to non-radiative recombination losses in perovskite solar cells, and evaluate their impact on device performance are analyzed, and some notable advances in mitigating these losses are highlighted.
Abstract: Photovoltaic solar cells based on metal halide perovskites have gained considerable attention over the past decade because of their potentially low production cost, earth-abundant raw materials, ease of fabrication and ever-increasing power conversion efficiencies of up to 25.2%. This type of solar cells offers the promise of generating electricity at a more competitive unit price than traditional fossil fuels by 2035. Nevertheless, the best research cell efficiencies are still below the theoretical limit defined by the Shockley-Queissier theory owing to the presence of non-radiative recombination losses. In this Review, we analyse the predominant pathways that contribute to non-radiative recombination losses in perovskite solar cells, and evaluate their impact on device performance. We then discuss how non-radiative recombination losses can be estimated through reliable characterization techniques, and highlight some notable advances in mitigating these losses, which hint at pathways towards defect-free perovskite solar cells. Finally, we outline directions for future work that will push the efficiency of perovskite solar cells towards the radiative limit.

644 citations

Journal ArticleDOI
TL;DR: NTE is reviewed in functional materials of ferroelectrics, magnetics, multiferroics, superconductors, temperature-induced electron configuration change and so on, in which NTE is determined by either ferroelectric order or magnetic one.
Abstract: Negative thermal expansion (NTE) is an intriguing physical property of solids, which is a consequence of a complex interplay among the lattice, phonons, and electrons. Interestingly, a large number of NTE materials have been found in various types of functional materials. In the last two decades good progress has been achieved to discover new phenomena and mechanisms of NTE. In the present review article, NTE is reviewed in functional materials of ferroelectrics, magnetics, multiferroics, superconductors, temperature-induced electron configuration change and so on. Zero thermal expansion (ZTE) of functional materials is emphasized due to the importance for practical applications. The NTE functional materials present a general physical picture to reveal a strong coupling role between physical properties and NTE. There is a general nature of NTE for both ferroelectrics and magnetics, in which NTE is determined by either ferroelectric order or magnetic one. In NTE functional materials, a multi-way to control thermal expansion can be established through the coupling roles of ferroelectricity-NTE, magnetism-NTE, change of electron configuration-NTE, open-framework-NTE, and so on. Chemical modification has been proved to be an effective method to control thermal expansion. Finally, challenges and questions are discussed for the development of NTE materials. There remains a challenge to discover a “perfect” NTE material for each specific application for chemists. The future studies on NTE functional materials will definitely promote the development of NTE materials.

492 citations

Journal ArticleDOI
TL;DR: The focus is on the origin of the various voltage-limiting mechanisms in PSCs, and the effect of such methods on the reduction of hysteresis are described.
Abstract: Metal-halide perovskites are rapidly emerging as an important class of photovoltaic absorbers that may enable high-performance solar cells at affordable cost. Thanks to the appealing optoelectronic properties of these materials, tremendous progress has been reported in the last few years in terms of power conversion efficiencies (PCE) of perovskite solar cells (PSCs), now with record values in excess of 24%. Nevertheless, the crystalline lattice of perovskites often includes defects, such as interstitials, vacancies, and impurities; at the grain boundaries and surfaces, dangling bonds can also be present, which all contribute to nonradiative recombination of photo-carriers. On device level, such recombination undesirably inflates the open-circuit voltage deficit, acting thus as a significant roadblock toward the theoretical efficiency limit of 30%. Herein, the focus is on the origin of the various voltage-limiting mechanisms in PSCs, and possible mitigation strategies are discussed. Contact passivation schemes and the effect of such methods on the reduction of hysteresis are described. Furthermore, several strategies that demonstrate how passivating contacts can increase the stability of PSCs are elucidated. Finally, the remaining key challenges in contact design are prioritized and an outlook on how passivating contacts will contribute to further the progress toward market readiness of high-efficiency PSCs is presented.

393 citations