Flexible Solar-Blind Photodetectors Based on β-GaO Films Transferred by a Stamp-Based Printing Technique

A stamp-based printing technique was applied to transfer the $\beta $ -Ga $_{{2}}\text{O}_{{3}}$ films grown by pulsed laser deposition (PLD) from Si substrates onto some flexible substrates, such as PET, PEN, and PI. It is demonstrated that the $\beta $ -Ga $_{{2}}\text{O}_{{3}}$ -based flexible solar-blind photodetectors (SBPDs) exhibit brilliant optoelectrical performances with a low dark current of 1.7pA at 10V, a $\text{I}_{ {254} \text {nm}}/\text{I}_{ \text {dark}}$ ratio of ${1.2} \times {10}^{{3}}$ , rise ( $\tau _{r\,{1}}$ =0.079s and $\tau _{r\,{2}}$ =0.413s) and decay ( $\tau _{d\,{1}}$ =0.029s and $\tau _{d\,{2}}$ =0.316s) times. In a further step, flexible imaging sensor arrays based on the $\beta $ -Ga $_{{2}}\text{O}_{{3}}$ /PET were fabricated, which exhibit good imaging capability and resolution. Moreover, wearable UVC-alarms based on the $\beta $ -Ga $_{{2}}\text{O}_{{3}}$ /PET were realized to monitor the UVC radiation in the environment in real time, which can be used in the COVID-19-related area.