Oxide Semiconductor Phototransistor with Organolead Trihalide Perovskite Light Absorber

A hybrid phototransistor is developed with solution-processed organolead trihalide perovskite (MAPbI(3)) capping indium gallium zinc oxide (IGZO), which well fuses the properties of the two materials in sensitive photodetecting and high-mobility charge transporting, respectively. The MAPbI(3)-capped IGZO phototransistor demonstrates excellent responsivities of over 25 mA W-1 for lights with photon energies above the bandgap of perovskite light absorber. Besides the high sensitivity to light in both ultraviolet and visible regions, hybrid phototransistor maintains a fair on/off ratio of over 106 in the dark, and a field effect mobility of 12.9 cm(2) V-1 s(-1). The perovskite light absorber also obviates the long-standing problem for metal oxide phototransistor, the persistent photoconductivity behavior. Furthermore, fast transient response has been achieved by showing rise-time and fall-time within tens of milliseconds. The newly developed device opens variable optic-electric sensing applications for the integrated oxide-perovskite hybrid phototransistors.