Ambipolar solution-processed CH 3 NH 3 PbBr 3 perovskite phototransistors with ultra-thin Al2O 3 protective layer

Organic-inorganic halide perovskite materials are attracting great attention for their excellent photoelectronic properties. Here we report the CH 3 NH 3 PbBr 3 perovskite phototransistors with bipolar behaviors. The photoresponsivity of the perovskite devices reaches 4 AW -1 on $\mathrm {V}_{GS}= -2.2$ V. In addition, the stability of organolead halide perovskite phototransistors is further improved by inserting ultra-thin Al 2 O 3 protective layer. The solution-based process and excellent device performance facilitate CH 3 NH 3 PbBr 3 perovskite as candidate materials for photoelectronic applications.