High-performance chemical-bath deposited CdS thin-film transistors with ZrO2 gate dielectric

Abstract

We demonstrate high performance chemical bath deposited CdS thin-film transistors (TFTs) using atomic layer deposited ZrO 2 based high-k gate dielectric material. Our unique way of isolation of the CdS-based TFTs devices yielded significantly low leakage current as well as remarkable lower operating voltages (<5V) which is four times smaller than the devices reported on CdS-based TFTs using SiO 2 gate dielectric. Upon thermal annealing the devices demonstrate even higher performance, including  FE exceeding 4 ± 0.2 cm 2 V -1 S -1 , threshold voltage V T of 3.8V and I on-off of 10 4 to 10 5 , which hold much promise for applications in future electronic and optical devices.

Nontoxic, Eco‐friendly Fully Water‐Induced Ternary Zr–Gd–O Dielectric for High‐Performance Transistors and Unipolar Inverters

“…Shan and co‐workers demonstrated that In 2 O 3 /ZrO x TFTs exhibit a saturation mobility of 3.08 cm 2 V −1 s −1 and an on/off current ratio of 10 8 . [12c] Pradhan and co‐workers fabricated CdS/ZrO x TFTs, which display a low operation voltage of 3.8 V and a field effect mobility of 4 cm 2 V −1 S −1 . Despite their attractive properties, the lower channel mobility still inhibits the realization of high‐performance ZrO x ‐based TFTs.…”

Fully solution-induced high performance indium oxide thin film transistors with ZrOx high-k gate dielectrics

“… 16 Pradhan et al fabricated CdS TFTs with ZrO 2 as the gate dielectric grown by chemical bath, which exhibits a low operation voltage of 3.8 V and a field effect mobility of 4 cm 2 V −1 s −1 . 30 Despite their attractive properties, however, TFTs based on high-k gate dielectric are usually realized using stringent and potentially costly manufacturing techniques. 7 The development of solution-derived dielectrics is still a step behind, inhibiting the realization of fully solution-processed TFTs with high performance.…”

Synthesis of CdS with Large Band Gap Values by a Simple Route at Room Temperature

“…The TEC15 glass was cleaned by micro-90, deionized water, and dried by high purity N2 (99.999%, 5N). For CdS deposition, the sputter chamber was pumped to a base pressure of~10 -4 Pa. After that, the CdS was deposited at room temperature, 3 Pa, 0.88 W•cm -2 rf power, 28.3 cm 3 •min -1 Ar gas (high purity: 5N) together with 0 (0% (volume fraction, φ)), 0.25 (0.88% (φ) ), 0.5 (1.78% (φ)), 0.75 (2.58% (φ)), and 1 (3.40% (φ)) cm 3 •min -1 O2 gas (high purity: 5N). The thickness of the CdS was 100 nm measured by an in situ optical transmission thickness apparatus.…”

“…Cadmium sulfide (CdS) is an II-VI group semiconductor with a direct band gap of 2.4 eV (bulk CdS) at room temperature. 1 It has potential use in a wide range including photovoltaic cells, 2 thin-film transistors, 3 light-emitting diodes, 4 phosphors, 5 biological labeling, 6 etc. Due to its low electrical resistivity and high optical transmittance, CdS films are commonly used as a buffer layer material in thin film solar cells such as CdTe, CuInGaSe and so on.…”