Scope and Objectives

1. To develop ultra-high efficiency infrared photodetectors based on silicon and germanium single nanowires and their arrays for military applications using MSM and transistor devices. 2.Fabrication of CMOS compatible devices using VLS and chemically etched nanowires using electron and focussed ion beam lithography techniques. 3.Device testing: Responsivity, Signal to noise ratio, frequency bandwidth. 4. Demonstration of a prototype for IR and THz detectors with high responsivity and detectivity.

Deliverables

Ultra -high efficiency CMOS nanowire photodetectors to detect light power belowpW. Germanium single nanowire MSM photodetector: Responsivity >1A/W, wavelengths range:800-1700 nm2. Development of junctionless transistor technology for THz radiation detection. Range: 0.3-0.9 THz, Voltage responsivity>1V/W,Silicon single nanowire MSM photodetectors:Responsivity higher than 103 A/W, wavelengths range: (600-1000 nm), Detectivity higher than:5x1011 cm.Hz1/23. Building of prototypes of the above devices/W IMPRINT Proposal (5318):Ultra -high efficiency CMOS compatible Si/Ge Single Nanowire Photodetectors in Infrared andTHz Wavelengths for Defence and Security Applications.

Scientific Output

1. Development of technology for infrared detector 2. Improvement of performance by using nanowire 3. Understanding the interaction of THz E-M wave in nano materials

Results and outcome till date

Developed polarization sensitive nanowire photodetectors Silicon Nanowire phototransitors with different nanoeire diameter was fabricated and tested. Heterojunction photodetector based on Ge-MoSe2 heterojunction was fabricated and characterized for self powered photodetector applications. Flexible photodetector based on MoSe2 on PET substrate was fabricated. Germanium Micro disk photodetectors were fabricated and characterised

Societal benefit and impact anticipated

Security and defence applications

Next steps

1. Fabrication of arrays of nanowire IR detector 2. THz detector fabrication and testing using MBE grown Ge epilayer on SOI 3. Prototyping of IR detectors

Publications and reports

Highly Responsive, Polarization Sensitive, Self-biased Single GeO2 Ge Nanowire Device for Broadband and Low Power Photodetectors, S Mukherjee, K Das, S Das, SK Ray, ACS Photonics 5 4170 2018 Self-powered room temperature broadband infrared photodetector based on MoSe2/Germanium heterojunction with 35A/W responsivity at 1550 nm Veerendra Dhyani, Mrinmay Das, Wasi Uddin, Pranaba Kishor Muduli, Samaresh Das. Appl. Phys. Lett. 114, 121101, 2019. Low cost flexible 1.1 um -1.6 um photodetector fabricated by hydrothermal grown large area MoSe2 nanostructures Veerendra Dhyani, Preeti Kumari, Sarmistha Maity, Samaresh Das. Proceedings Volume 11028, Optical Sensors 2019. Diameter-dependent photoresponse with high internal gain in a back gated single Si nanowire phototransistor. Veerendra Dhyani, Alka Jakhar, John Wellington J and Samaresh Das. J. Phys. D: Appl. Phys. 52, 425103, 2019.

Patents

One Submitted to IIT patent office

Scholars and Project Staff

Two PhD full time, two Research Associate full time

Challenges faced

Other information

The project has officially started on 24/08/2017 after the release of first installment of grant