Tag : Photoresponse

Roorkee (The Hawk): A team of researchers at the Indian Institute of Technology Roorkee (IIT Roorkee) led by Prof. Davinder Kaur, Dept of Physics, IIT Roorkee, along with the National Physical Laboratory, India, have been able to fabricate two Semiconductor-Insulator-Semiconductor (SIS) heterojunctions based Near-infrared (NIR) photodetectors for Ultrafast photoresponse by direct current (dc) magnetron sputtering technique. The DC magnetron sputtering process involves a vacuum chamber containing the target material parallel to the target substrate. The vacuum chamber contains a high-purity inert gas such as argon that becomes charged when exposed to a pulsed DC current. The results demonstrate that SIS heterojunctions with an excellent carrier transport mechanism are potential candidates in next-generation ultrafast optoelectronics applications. The response time for both SIS n-MoS2/p-Si and n-MoS2/AlN/p-Si heterojunctions are found to be 0.3378 AW-1 and 1.865 AW-1 for visible radiations (532 nm) and 0.1245 AW-1 and 1.4743 AW-1 for NIR radiations (1064 nm), respectively. The response time (rise time and decay time) of the fabricated heterojunction decreased from 47.30 µs and 56.58 µs to 3.32 µs and 4.73 µs with the insertion of an ultrathin insulating AIN layer (plasma enhanced layer). This effort is a step before the new age of SIS heterostructure-based ultrafast-photovoltaic devices with the foremost carrier-tunnelling mechanism. Numerous photodetectors have been developed with a significant photoresponse and using inorganic, organic and perovskite materials such as Silicon (Si), Gallium arsenide (GaAs), Zinc Oxide (ZnO), among others. Most of these photodetectors have certain limitations, such as relatively slow or less detection ...