10:45 〜 11:00
[E-6-01] Using thin-film transistor with thick oxygen-doped SZTO channel and patterned Pt/NiO capping layer to enhance ultraviolet light sensing performance
To enhance photodetection performance of thin-film transistor (TFT)-based UV photodetectors, it typically requires thick channel layers to facilitate high photocurrent (Iph), while thin channel layers are needed to ensure complete depletion channel to suppress dark current (Idark). In this work, to maximize the channel thickness (Tch) while minimizing the trade-off between Iph and Idark, O2 is introduced into the SZTO channel during sputter deposition to reduce carrier concentration, in addition, a stack of Pt/NiO capping layers (CLs) is proposed to simultaneously reduce the effective Tch (Tche) of the entire depletion channel and increase Iph. Note that Pt CL forms a Schottky contact with the SZTO channels to reduce Tche, and NiO CL forms a pn heterojunction with the SZTO channel, provide additional photogenerated carriers and enhance Iph under UV irradiation. Experimental results show that the proposed 95-nm-thick O2-doped SZTO TFT with stacked Pt/NiO CLs exhibits excellent photoresponsivity of 2026 A/W and photosensitivity of 9.3×107 A/A, which are about 75× and 85× higher than the traditional 45-nm-thick SZTO TFT under 275 nm UV irradiation.