Currently, the area of photovoltaics become revolutionized by newly emerging solar cells, organometal halide hybrid perovskites solar cell with its most recent efficiency jumps from 23% 1 into 29.15%. Remarkably, CH 3 NH 3 PbI 3 -based perovskites have very long electron and hole carrier diffusion lengths, high optical absorption, unique defect properties. Furthermore, recent theoretical and experimental results have shown that CH 3 NH 3 PbI 3 exhibits ambipolar self-doping properties: both good p-type and n-type conductivities can be realized by manipulating the growth conditions. Beside the exceptional high efficiency and V OC , lead halide perovskites are also capable of bandgap tuning from about 1.5 eV (CH 3 NH 3 PbI 3 ) to 2.2 eV (CH 3 NH 3 PbBr 3 ) by changing the compositions of perovskites. This capability makes lead halide perovskites as ideal candidates for all perovskites thin-film tandem cell and other optoelectronic device applications.