In-Situ IGZO/ITON Heterostructure Phototransistor to Enhance Visible Light Detection

We present an in-situ IGZO/ITON heterojunction phototransistor with exceptional performance under visible light. By introducing a low bandgap of ITON as a light absorption layer, the responsivity of 30.2 A/W, photosensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.3\times 10^{{4}}$ </tex-math></inline-formula>, and detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.8\times 10^{{13}}$ </tex-math></inline-formula> Jones under red light illumination (635nm). Because the ITON was deposited by the sputtering with controlling Ar/N<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas mixture condition immediately after IGZO deposition without breaking the vacuum, the suggested structure is not only compatible with the conventional large-area manufacturing process but also minimizes the interfacial defects between IGZO and ITON.