Fig. 5.

Logic inverter using red- and green-quantum dot phototransistors. a Photoresponses of 1RQ- and 1GQ-OQO phototransistors with respect to incident light wavelengths. Both transistors exhibit photoresponses at 500-nm wavelength illumination. For 570-nm-wavelength irradiation, the photoresponse is only observed for the 1RQ-OQO devices. b Stacked configuration of 1RQ- and 1GQ-OQO phototransistors prepared on transparent glass substrates for logic inverters. c Electro-optical NOT gate circuitry and resultant logic table. d Time-domain measurement of V _out at alternated 500- and 570-nm illumination wavelengths