Exploring Emerging Photovoltaic Materials Beyond Perovskite: The Case of Skutterudite

Because of the stability and toxic issue of CH3NH3PbI3, great efforts have been made to search emerging materials beyond perovskite. Most of the explorations are based on ns(2)-containing compounds, because lone-pair s-orbital-derived antibonding states are believed to play a crucial role in unique properties of CH3NH3PbI3. In this work, we chose skutterudite-structure IrSb3 (Eg approximate to 1.3 eV) as a case study to show that the strong antibonding character at valence band maximum (VBM) can appear without the contribution from lone-pair s orbital. First-principles calculations show that IrSb3 possesses similar electronic properties as CH3NH3PbI3: (i) ambipolar conductivity with much better electron and hole effective masses than that of CH(3)NH(3)PbI3; (ii) strong optical absorption (similar to 1 X 10(4) cm(-1)); (iii) shallow dominating defects. More importantly, IrSb3 is much more stable than CH3NH3PbI3. Our work may shed light on searching new promising solar cell materials beyond ns(2)P-containing perovskite.