Heterogeneous metal oxide channel structure for ultra-high sensitivity phototransistor with modulated operating conditions

In this study, a thin-film transistor with a heterogeneous channel structure was introduced into oxide semiconductors to improve their electrical properties, which resulted in high mobility and lower subthreshold swing (S.S.). To effectively improve the ability of devices for ultraviolet (UV) light sensing, we used the concept of a Sn-doped indium gallium zinc oxide middle layer in the channel, which can effectively reduce the energy band, localized states, and deep level traps. In addition, a higher Zn content in the top and bottom layers was used to achieve the buried channel design for enhancing the overall properties of the devices. Using electron-hole pair recombination, the operating parameters, such as pulse width in an illuminated state and drain sensing voltage in dark conditions, were optimized. A high sensitivity, ultra-high-endurance phototransistor was developed, and the results indicated that the reliability of UV sensing can be effectively enhanced.