A self-powered HgTe quantum dots/PBDB-T:Y6 bipolar broadband photodetector for logic gates

Optoelectronic logic gates (OELGs) have become one of the excellent candidates for logic devices in the post Moore era, with great potential for complex optical computing, secure optical communication, and image processing. As an important component of OELGs, bipolar photodetectors (BPDs) face problems such as limited logic functionality, narrow response range, slow response speed, and high-power consumption. Here, we propose a self-powered BPD with a back-to-back structure based on HgTe quantum dot (QD) and organic material PBDB-T:Y6 stacking. The results show that the BPD exhibits a broadband bipolar photoresponse (300-1800 nm) under a bias voltage of 0 V, with a rapid response speed in the microsecond range. By modulating the device with three light sources within the positive and negative photoresponse wavelength ranges, the HgTe QDs/PBDB-T:Y6 BPD successfully achieves five logic gate operations ("OR", "AND", "NAND", "NOR", and "NOT"). Based on excellent fast and broadband bipolar optoelectronic response, we further confirm the potential application of the HgTe QDs/PBDB-T:Y6 BPD in broadband optical communication encryption. This work provides a useful reference for the combination of QDs and organic materials in the development of high-performance BPDs.