PbS Colloidal Quantum Dots/ZnO/Si Hybrid Photodiode with Various Reverse Bias Voltages

Abstract

We have realized an infrared (IR) photodiode with silicon for the future beyond-VLSI photonics. Colloidal quantum dot (CQD) integration with Si is a simple process. We previously reported a PbS CQD/ZnO/Si hybrid IR photodiode. The device had an absorption peak at 1230 nm. To improve the quantum efficiency, we investigated the dose levels of Si substrates and improved the external quantum efficiency (EQE) by using a structural approach, such as using a higher doping level of Si. We achieved a 1230 nm absorption peak with an ITO/Au/PbS-EDT/PbS-I CQDs/ZnO/Si hybrid IR photodiode with an EQE close to 7%, at a reverse bias of -0.5 V.