Codesigning Alloy Compositions of CdSeyTe1−y Absorbers and MgxZn1−xO Contacts to Increase Solar Cell Efficiency. Issue 9 (20th July 2022)

• Record Type: Journal Article
• Authors: Khan, Imran S.; Ablekim, Tursun; McGott, Deborah L.; Good, Brian; Perkins, Craig L.; Metzger, Wyatt K.; Zakutayev, Andriy
• Is Part Of: Solar RRL. Volume 6:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-20
• Subjects: cadmium telluride -- combinatorial -- interfaces -- magnesium zinc oxide -- thin film solar cells; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202200394
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Thin‐film solar cells such as CdTe are a major commercial photovoltaic technology, with more than 25 GW installed worldwide and levelized costs of electricity competitive with fossil fuels. Further progress may result from integrating CdSe y Te1− y absorbers with Mg x Zn1− x O contacts, but the device efficiency is difficult to maximize due to coupled dependence on chemical composition of both alloys. Herein, a high‐throughput approach is demonstrated to codesign chemical compositions in alloyed Mg x Zn1− x O/CdSe y Te1− y thin‐film solar cells, using combinatorial libraries of PV devices with orthogonal composition gradients in CdSe y Te1− y absorbers and Mg x Zn1− x O contacts. It is found that the solar cell performance is a strong and coupled function of both elemental compositions, with efficiency up to 17.7% ( V OC = 836 mV, fill factor = 69%, J SC = 30.6 mA cm −2 ) at atomic compositions of Mg/(Mg + Zn) ≈18% and average Se/(Se + Te) ≈4%. These performance trends among >100 devices are explained by >100 ns lifetime of photoexcited charge carriers at the Mg x Zn1− x O/CdSe y Te1− y interface where strong Se accumulation is also observed. This study reports the optimal compositions of the commercially relevant Mg x Zn1− x O/CdSe y Te1− y solar cells and demonstrates a general approach to codesigning performance of alloyed thin‐film solar cells and other optoelectronic devices. Abstract : A high‐throughput experimental approach to codesign alloyed contact and absorber for thin film solar cells is demonstrated. For commercially relevant Mg x Zn1− x O/CdSe y Te1– y devices, the solar cell performance has a strong and coupled dependence on both elemental compositions. Performance trends among >100 devices show efficiency up to 17.7%, explained by optimized bandgaps and photoexcited charge carrier lifetime >100 ns at the interface.