Organic-inorganic hybrid perovskites ABI(3) (A = CH3NH3, NH2CHNH2; B = Sn, Pb) as potential thermoelectric materials: a density functional evaluationt

To assess the feasibility of the organic-inorganic perovskite iodides ABI(3) (A = CH(3)NH3, NH2CHNH2; B = Sn, Pb; X =1) for thermoelectric applications, we estimated their figures of merit (ZTs) as well as that of Bi2Te3, which is optimized for temperatures around 300 K, as a function of chemical potential on the basis of density functional theory calculations. Our analysis employed the tetragonal structures (P4mm) of (CH3NH3)PbI3 and (CH3NH3)(5)nI(3), the trigonal (P3m1) structure of (NH2CHNH2)PbI3, and the orthorhombic (Amm2) structure of (NH2CHNH2)SnI3 to examine their thermoelectric properties around room temperature. Our work reveals that the ZTs of electron-doped ABI(3) perovskites can be as large as that of hole-doped Bi2Te3 whereas those of hole-doped ABI(3) are rather smaller so that, in thermoelectric performance, electron-doped perovskites ABI(3) can be as good as hole-doped Bi2Te3.