Improved Photoresponse Performance of Self Powered ZnO/Spiro MeOTAD Heterojunction Ultraviolet Photodetector by Piezo Phototronic Effect.
Strain induced piezoelectric potential (piezopotential) within wurtzite structured ZnO can engineer the energy band structure at a contact or a junction and, thus, enhance the performance of corresponding optoelectronic devices by effectively tuning the charge carriers' separation and transport. Here, we report the fabrication of a flexible self powered ZnO/Spiro MeOTAD hybrid heterojunction ultraviolet photodetector (UV PD) The obtained device has a fast and stable response to the UV light illumination at zero bias. Together with responsivity and detectivity, the photocurrent can be increased about 1 fold upon applying a 0.753% tensile strain. The enhanced performance can be attributed to more efficient separation and transport of photogenerated electron hole pairs, which is favored by the positive piezopotential modulated energy band structure at the ZnO Spiro MeOTAD interface. This study demonstrates a promising approach to optimize the performance of a photodetector made of piezoelectric semiconductor materials through straining.
ACS applied materials interfaces