UV response of IGZO tunnel-contact SGTs for low-power and high-sensitivity UV sensor applications

Abstract

We present the fabrication of IGZO tunnel-contact source-gated transistors (SGTs) and a detailed investigation of their ultraviolet (UV) sensing characteristics. In the present study, we use indium gallium zinc oxide (IGZO), a material commonly used in oxide thin-film transistors (TFTs), to fabricate SGTs. We then demonstrate their applicability as UV sensors. As a novel class of TFTs, SGTs exhibit a substantially lower saturation voltage and lower power consumption than conventional ohmic-contact TFTs, which is achieved through the intentional introduction of tunneling layers to create an energy barrier. In addition, these SGTs demonstrate higher responsivity and detectivity than similarly scaled TFTs lacking energy barriers. The enhanced responsivity and detectivity highlight their applicability as high performing UV sensor. To explore this potential, we evaluated the efficacy of sunscreen cream in blocking UV light by analyzing the current-voltage (I-V) characteristics of the SGT devices underneath the sunscreen; the proposed devices should be useful in the healthcare and cosmetics industries.