Gated three-terminal device architecture to eliminate persistent photoconductivity in oxide semiconductor photosensor arrays

Abstract

The composition of amorphous oxide semiconductors, which are well known for their optical transparency, can be tailored to enhance their absorption and induce photoconductivity for irradiation with green, and shorter wavelength light. In principle, amorphous oxide semiconductor-based thin-film photoconductors could hence be applied as photosensors. However, their photoconductivity persists for hours after illumination has been removed, which severely degrades the response time and the frame rate of oxide-based sensor arrays. We have solved the problem of persistent photoconductivity (PPC) by developing a gated amorphous oxide semiconductor photo thin-film transistor (photo-TFT) that can provide direct control over the position of the Fermi level in the active layer. Applying a short-duration (10 ns) voltage pulse to these devices induces electron accumulation and accelerates their recombination with ionized oxygen vacancy sites, which are thought to cause PPC. We have integrated these photo-TFTs in a transparent active-matrix photosensor array that can be operated at high frame rates and that has potential applications in contact-free interactive displays.

Ultrasensitive organic phototransistors with multispectral response based on thin-film/single-crystal bilayer structures

“…30 They also represent a large improvement over OPTs based on amorphous oxide semiconductors, where persistent photoconductivity (PPC) can last for several hours or days. 31 As reported for other OPTs, s d can be improved to less than 0.5 s (i.e., the temporal resolution of our setup) by applying a short gate pulse (2s, V GS ¼ À10 V), which causes a full release of -reset), and <0.5 s (with gate-reset), respectively, and rise time of s r faster than 500 ms.…”

Quasi Two-Dimensional Dye-Sensitized In2O3 Phototransistors for Ultrahigh Responsivity and Photosensitivity Photodetector Applications

“…3 High responsivity, high photosensitivity, low noise, and stable performance have always been key factors in the assessment of a good photodetector, but now extra demands are being made of these devices.…”

“…From these measurements we show that dye-sensitization increases the device photosensitivity and responsivity to all incident wavelengths, with the biggest effect observed under green light illumination. Best performing phototransistors exhibit a maximum responsivity of ~2×10 3 A/W and a photosensitivity of 1×10 6 . Due to its ultrathin nature, the photoactive In2O3/D102 layer is extremely transparent with a minimum transmission of 92 % across all visible wavelengths (400-700 nm).…”

Dual Mode Photocurrent Generation of Graphene-Oxide Semiconductor Junction

“…24,25,38 "V" configuration shows the maximum photocurrent responsivity of 10.3 μA/W at 3.08 eV (403 nm). Unlike "L" configuration, the responsivity increases as the illumination energy increases.…”