Fig. 6

Transfer characteristics for HJPT photo-inverters. a Schematic of a PMOS-like HJPT photo-inverter to resemble a common-source amplifier for assessing the phototransistor performance metric. VDD, VIN and VOUT stand for supply voltage, input voltage signal and output voltage signal, respectively. b,c, Transfer characteristics (VOUT vs. VIN) measured using a 475-nm LED light source under different incident light intensities for photo-inverters composed of HJPTs using b FACs/C16-IDTBT and c FACs/C8-BTBT. d, e Corresponding intrinsic amplification (Ai) obtained for d FACs/C16-IDTBT and e FACs/C8-BTBT. f, g Effect of incident optical power density on VOUT measured at a fixed voltage supply VDD of −10 V for different VIN biases for the f FACs/C16-IDTBT photo-inverter and g FACs/C8-BTBT photo-inverter