Carrier-selective crystalline silicon heterojunction (SHJ) solar cells have already reached superior lab-scale efficiencies. Besides judicious wafer thickness design, the optimal choice of passivation schemes and carrier-selective materials is essential for industry adoption. Appropriate reduction of process complexity and performance benefits through minimal recombination losses are key. Thus, along with well-designed back contacts, the development of low-temperature processable transparent passivating stacks that act as carrier-selective contacts (CSCs) is highlighted for their potential in circumventing the limited open-circuit photovoltage and contact-related losses in mainstream solar cells. In this review, effective passivation schemes deploying materials ranging from undoped metal oxides (MOs) to doped silicon are evaluated, with a focus on their significance for industrially viable passivating contact development. Passivation stack architectures with SiOx/heavily doped polycrystalline silicon (n+-/p+-poly-Si) realize the most attractive polysilicon-on-oxide (POLO) junctions and related schemes, e.g., combined with tunnel oxide passivated contact (TOPCon) and interdigitated back contact (IBC) solar cells. It is envisioned that the industrial trend is to eventually shift from the p-Si passivating emitter rear contact (PERC) and passivated emitter and rear polysilicon (PERPoly), towards TOPCon architectures, due to high manufacturing yields and compatibility with large-area metal screen printing and alternative bifacial designs.
|Original language||English (US)|
|State||Published - Jan 29 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-05-25
Acknowledgements: Dr. B.K.G. would like to thank University Malaysia Sabah (UMS) and he is greatly indebted to Prof. K-W.A.C. of the University of Science and Technology of China (USTC) for accepting him into the opportunity to collaborate on this work. The crystalline silicon photovoltaic technology and cost roadmaps, Andrés Cuevas (Australian National University), Stefaan De Wolf (King Abdullah University of Science and Technology), Christophe Ballif (Ecole Polytechnique Fédérale de Lausanne), Matin Hermle (Fraunhofer), Kenji Yamamoto (Kaneka Corporation), and Martin Green (University of New South Wales), are credited for instigating the writing of this review, and their invaluable reports have been key references. This work was supported by the Chinese Academy of Sciences (CAS). The award of various other funding sources is acknowledged by K-W.A.C. such as the National Key Research and Development of China (2018 TFB1500103), Zhejiang Energy Group (znk-2018-118), the Ministry of Education of the P.R.C. (111 Project 2.0: BP0719016), BK21 project of the Ministry of Education of Korea, National Natural Science Foundation of China (61650110517)) and Natural Science Foundation of Ningbo (2017A610095). The authors have no conflicts to disclose.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering