Bandgap Engineering of Lead‐Free Double Perovskite Cs2AgBiBr6 through Trivalent Metal Alloying

• DOI: 10.1002/anie.201703970
• Publication Date: 2017-05-19T01:47:01Z
• Authors: Ke‐zhao Du; Weiwei Meng; Xiaoming Wang; Yanfa Yan; David B. Mitzi
• Keywords: Lead (geology)

Abstract The double perovskite family, A 2 M I III X 6 , is a promising route to overcome the lead toxicity issue confronting current photovoltaic (PV) standout, CH 3 NH PbI . Given generally large indirect band gap within most known perovskites, band‐gap engineering provides an important approach for targeting outstanding PV performance this family. Using Cs AgBiBr as host, through alloying of In /Sb has been demonstrated in work. Ag(Bi 1− x )Br (M=In, Sb) accommodates up 75 % with increased gap, and 37.5 Sb reduced gap; that is, enabling ca. 0.41 eV modulation introduction two metals, smallest value 1.86 0.625 0.375 Band structure calculations indicate opposite shift directions associated Sb/In substitution arise from different atomic configurations these atoms. Associated photoluminescence environmental stability three‐metal systems are also assessed.