Hybrid graphene-InAs/GaInSb type-II superlattice infrared photodetectors

This study demonstrates that graphene can boost the performance of type-II superlattice (T2SL) infrared photodetectors. The devices were fabricated by simply forming graphene transistors or graphene diodes on InAs/GaInSb T2SLs, in contrast to recent structures that are grown using complex crystal growth and bandgap engineering techniques. The infrared detection performance of the devices was evaluated using infrared irradiation from the top of the device. The long wavelength infrared performance of the T2SL was improved by a factor of 217, and the T2SL-based graphene diodes exhibited the lowest noise equivalent power value of 4.09 × 10 −12 W/Hz 1/2 and the highest detectivity value of 3.66 × 10 8 cm · Hz 1/2 /W while the T2SL diodes without the graphene exhibited those of 8.87 × 10 −10 W/Hz 1/2 , and 1.69 × 10 6 cm · Hz 1/2 /W, respectively. These findings indicate the potential to improve infrared image sensor performance by incorporating graphene.