An optoelectronic device is provided, the device comprising an active layer comprising organometal halide perovskite and a hole transport layer (HTL) formed by vacuum evaporation and configured to transport hole carriers. The HTL includes a first sublayer comprising a hole transport material (HTM) doped with an n-dopant and disposed adjacent to the active layer, a second sublayer comprising the HTM that is undoped and disposed adjacent to the first sublayer, and a third sublayer comprising the HTM doped with a p-dopant and disposed adjacent to the second sublayer. The doping concentration of the n-dopant for the n-doped sublayer is determined to match the highest occupied molecular orbital energy level of the n-doped sublayer with the valence band maximum energy level of the perovskite active layer.