Context: Recently, the researchers from Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute under the Department of Science and Technology, have developed 'Photodetectors'.
About Photodetectors

• The scientists have fabricated an economical and energy-efficient wafer-scale photodetector (thin slice-based) using gold-silicon interface, for security applications.
• It could help detect weak scattered light as an indication of unwanted activity.
• They are the heart of any opto-electronic circuit that can detect light and are employed for a wide variety of applications ranging from controlling automatic lighting in supermarkets to detecting radiation from outer galaxy as well as security-related applications.
• The scientists have fabricated gold (Au)-silicon (n-Si) interface, which showed high sensitivity towards light demonstrating the photodetection action.
• The Au–Si interface was brought about by galvanic deposition, a technique for electroplating of metals, wherein water-based solutions (electrolytes) are used, which contain the metals to be deposited as ions.
• The metal nanostructures enhanced the performance of the fabricated detector through trapping the incoming light. This photodetector displayed long-term environmental stability.
• The detector exhibits a rapid response of 40 microseconds and can detect low light intensities.
• The device covers a broad spectral range from Ultraviolet to Infrared.
• The detector operates in self-powered mode, which means the device does not require external power for its operation, thus making it energy efficient.