Direct on chip cadmium sulfide thin film transistors synthesized via modified chemical surface deposition

Abstract

A simple and inexpensive solution-based method to grow functional and continuous nano-crystalline CdS thin films is demonstrated. The resulting CdS films are used to fabricate n-type thin film transistors (TFTs) with field effect mobility as high as ∼0.55 cm² V⁻¹ s⁻¹, a threshold voltage (V_T) of ∼8.4 V, and an on/off current ratio of 10⁶. This method utilizes a solid-state reaction at low temperature that eliminates the need for nanoparticle synthesis to fabricate the semiconducting layer in the TFTs. The method also promotes efficient usage of the chemical precursors, which further reduces the cost of the process. This is a promising method that could be easily implemented in a manufacturable process such as roll-to-roll.