High external quantum efficiency in ZnO/Au/Ga2O3 sandwich-structured photodetector

In this study, sandwich-structured photodetector (SSPD), a new type of structure of PD based on traditional metal-semiconductor-metal (MSM) structure, was designed and fabricated to solve the difficult problem of weak light detection caused by the low gain of PDs with the traditional structure. Herein, zinc oxide/gold/gallium(III) oxide (ZnO/Au/Ga2O3) SSPD with a high external quantum efficiency (EQE) was successfully constructed by growing Ga2O3 film layer on the electrode area of the ZnO/Au MSM-structured device. The high EQE originates from the backlight-type irradiation and embedded electrodes of the special sandwich structure existing in the ZnO/Au/Ga2O3 SSPD. The ZnO/Au/Ga2O3 SSPD shows EQE of up to 11626 % at 30 V, which is 18 times (654 %) higher than that of the traditional MSM-structured ZnO/Ga2O3/Au PD. These results indicate that the research provides a new and effective method to increase the performance of Ga2O3-based PDs.

Automated summary

A new sandwich-structured photodetector (SSPD) was designed and fabricated to solve the problem of weak light detection in traditional metal-semiconductor-metal (MSM) photodetectors. A high external quantum efficiency (EQE) was achieved by growing Ga2O3 film layer on the electrode area of the ZnO/Au MSM-structured device. The ZnO/Au/Ga2O3 SSPD showed an EQE of up to 11626% at 30 V, which is 18 times higher than the traditional ZnO/Ga2O3/Au PD.