Preparation of a silicon heterojunction photodetector from colloidal indium oxide nanoparticles

• High performance In2O3 NPs/Si photodetector was prepared by laser ablation.
• The photodetector has high sensitivity to visible and near IR.
• XRD spectrum showed that In2O3 NPs is polycrystalline.
• The optical band gap of In2O3 NPs is about 3.95 eV.

A colloidal indium oxide (In2O3) nanoparticles (NPs) were synthesized by using a Q-switched Nd:YAG laser ablation of indium target in water at room temperature. Optical absorption and x-ray diffraction (XRD) investigation of the prepared samples confirm the formation of In2O3 NPs. A solution-processed silicon heterojunction photodetector, fabricated by drop cast film of colloidal In2O3 NPs onto n-type single crystal silicon wafer, is demonstrated. I–V characteristics of In2O3 NPs/Si heterojunction under dark and illumination conditions confirmed the rectifying behavior and the good photoresponse. The built-in-voltage was determined from the C–V measurements which revealed an abrupt junction.