Challenges and opportunities for an efficiency boost of next generation Cu(In, Ga)Se2 solar cells: prospects for a paradigm shift. Issue 7 (26th May 2020)

• Record Type: Journal Article
• Authors: Ochoa, Mario; Buecheler, Stephan; Tiwari, Ayodhya N.; Carron, Romain
• Is Part Of: Energy & environmental science. Volume 13:Issue 7(2020)
• Page Start: 2047
• Page End: 2055
• Publication Date: 2020-05-26
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d0ee00834f
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : A perspective on some strategies to trigger new developments for the next generation of Cu(In, Ga)Se2 solar cells is presented. Abstract : Cu(In, Ga)Se2 photovoltaic technology has notably progressed over the past years. Power conversion efficiencies above 23% were reached in spite of the polycrystalline nature of the absorber. Although efficiencies are still far from the practical limits, the material quality is approaching that of III–V compounds that yield the most efficient solar cells. The high carrier lifetime, low open circuit voltage deficit and external radiative efficiency in the single-digit percentage range suggest that the next efficiency boost may arise from the implementation of alternative device architectures. In this perspective paper, we describe the current challenges and pathways to enhance the power conversion efficiency of Cu(In, Ga)Se2 solar cells. Specifically, we suggest the use of non-graded absorbers, integration of charge selective contacts and maximization of photon recycling. We examine these concepts by a semi-empirical device modelling approach, and show that these strategies can lead to efficiencies of 29% under the AM1.5 global spectrum. An analysis of whether or not current state-of-the-art Cu(In, Ga)Se2 solar cells already benefit from photon recycling is also presented.