Metal Oxide Thin Film Phototransistor for Remote Touch Interactive Displays

Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

“…The channel architecture of the phototransistor is essential for maximizing photodetector performance. Phototransistors using only a BHJ channel have been shown to exhibit broad absorption spectra 34 , but the disordered nature of BHJs makes it difficult to approach mobilities of 1 18,29 and various metal oxides 35 operate as phototransistors, but their photonic performance is limited by low absorption outside the ultraviolet region due to their wide bandgaps. On the other hand, the properties of these devices can be combined by forming a heterojunction between a good absorber that efficiently generates electron-hole pairs and high-mobility semiconductor to rapidly transport the carriers out of the device 19,28,36,37 .…”

Origin of High Photoconductive Gain in Fully Transparent Heterojunction Nanocrystalline Oxide Image Sensors and Interconnects

“…[ 34 ] In the presented work, it can be argued that the SBL is mainly due to the increased electron density which corresponds to the number of the ionized oxygen vacancies. Based on the values of I DS in Figure 2 a, the external quantum effi ciency (EQE) can be retrieved using the following equation: [ 35 ] Adv. Mater …”

Temperature dependence of photocurrent in an amorphous GaInZnO/InZnO thin film transistor

“…12,13 For advantageous use of two active layers of a-IZO and a-GIZO (or a-HIZO), Jeon et al proposed a photosensor array with a double or triple active layer composed of IZO and GIZO (or HIZO). 11,14,15 The proposed TFTs showed stable threshold voltage (V th ) and photocurrent distributions for various device dimensions and aging times. Moreover, they could eliminate the persistent photoconductivity (PPC) effect, which acts as a hurdle for the adoption of oxide semiconductor materials into the optical sensor, 16 by rapidly controlling the oxygen vacancies using a gated three-terminal photosensor array.…”

“…14 Moreover, IZO has a high density of sub-gap states induced by oxygen vacancies, and these states act as a carrier source for supplying before band-to-band excitation. 15 Therefore, it is thought that an incident photon energy over than 2.82 eV was enough to excite a bound electron and increase the off current by greater than three orders of magnitude, independent of the thermal energy. In this respect, the slight decrease in the photocurrent with increasing temperature in the relatively high temperature region, where T > 90 C, might be interpreted as a decrease in the electron mobility by phonon scattering, rather than as a variation of the thermally generated carrier density.…”