Ultrahigh Responsivity In 2 O 3 UVA Photodetector through Modulation of Trimethylindium Flow Rate.

Oxygen vacancies (V_o) can significantly degrade the electrical properties of indium oxide (In₂O₃) thin films, thus limiting their application in the field of ultraviolet detection. In this work, the V_o is effectively suppressed by adjusting the Trimethylindium (TMIn) flow rate (f_TMIn). In addition, with the reduction of the f_TMIn, the background carrier concentration and the roughness of the film decrease gradually. And a smooth In₂O₃ thin film with roughness of 0.44 nm is obtained when the f_TMIn is 5 sccm. The MSM photodetectors (PDs) are constructed based on In₂O₃ thin films with different f_TMIn to investigate the opto-electric characteristics of the films. The dark current of the PDs is significantly reduced by five orders from 100 mA to 0.28 μA with the reduction of the f_TMIn from 50 sccm to 5 sccm. In addition, the photo response capacity of PDs is dramatically enhanced. The photo-to-dark current ratio (PDCR) increases from 0 to 2589. Finally, the PD with the f_TMIn of 5 sccm possesses a record-high responsivity of 2.53 × 10³ AW⁻¹, a high detectivity of 5.43 × 10⁷ Jones and a high EQE of 9383 × 100%. Our work provides an important reference for the fabrication of high-sensitivity UV PDs. [ABSTRACT FROM AUTHOR]