Nanomesh electrode on MgZnO-based metal-semiconductor-metal ultraviolet photodetectors

摘要

In this work, the nano-scaled mesh electrodes are fabricated by obliquely depositing metals through the highly ordered polystyrene nanosphere mask. Furthermore, the intrinsic MgZnO film is deposited as the absorption layer for the metal-semiconductor-metal ultraviolet photodetectors (MSM-UV-PDs) using the vapor cooling condensation system. The 100-nm-linewidth nanomesh electrodes with metal occupying a roughly 10% of the device surface region consequently render PDs with a high transmittance in the ultraviolet (UV) wavelength range. The photoresponsivity of MgZnO-based MSM-UV-PDs evaluated at the wavelength of 330?nm with the operating bias voltage of 5?V is elevated from 0.135 to 0.248?A/W when the thin metal electrode is replaced by the nanomesh electrode, and the corresponding quantum efficiency is improved from 50.75 to 93.23%. Finally, adopting the nanomesh electrode also helps to enhance the UV-visible rejection ratio (R_330nm/R_450nm) and the detectivity from 1663 and 1.78?×?1010?cmHz0.5W?1 to 2480 and 2.43?×?1010?cmHz0.5W?1, respectively.