Tag Archives: Nikhil Jain

Taking photos and videos in near darkness

Who hasn’t found wanted to take a picture in a situation where there’s very little light? It seems scientists at SUNY (State University of New York) College of Nanoscale Science and Engineering (CNSE) have found a way to solve the problem. From a Jan. 30, 2014 news item on Azonano,

When the lights went out at the big game, fans and film crews struggled to take a decent picture in the darkness. Those same folks will be cheering the latest research by a team of SUNY College of Nanoscale Science and Engineering (CNSE) scientists, which makes brilliant video and pictures possible even if the lights go out.

Dark and blurry low light photos could soon be a thing of the past, thanks to the development of game-changing ultrathin “nanosheets,” which could dramatically improve imaging technology used in everything from cell phone cameras, video cameras, solar cells, and even medical imaging equipment such as MRI machines.

As a result, this technology is perfectly suited for inclusion in a wide variety of everyday devices, including today’s smartphones, which are often used to take pictures, but suffer from limitations in low light environments. This research could allow even novice photographers to take sharper images, even in the midst of a blackout during the biggest game of the year.

A SUNYCNSE research profile titled: SUNY College of Nanoscale Science and Engineering Scientists Publish Game-Changing Semiconductor Nanosheets Research That Could Revolutionize Cameras in Low-Light Environments provides more technical details about the research,

Leading-edge research by a team of SUNY College of Nanoscale Science and Engineering (CNSE) scientists has been published in ACS Nano after the scientists evaluated ultrathin indium(III) selenide (In2Se3) nanosheets and discovered that their electrical resistance drops significantly when exposed to light. This effect, known as a photoconductive response, can be used to make a photodetector or light sensor, and because the two-dimensional nanosheets exhibited such a strong photoconductive response across a broad light spectrum and simultaneously resist chemical contamination, this research could lead to a revolution in extreme low-light, high-resolution imaging products and applications, such as consumer and professional cameras and video cameras, for example.

The team combined a variety of cutting-edge tools and methods, including scanning electron microscopy (SEM) to identify the nanosheets; atomic force microscopy (AFM) to measure their thickness; X-ray diffractometry (XRD) and selected area electron diffraction (SAED) combined with high-resolution images from transmission electron microscopy (TEM) to examine nano-layer details such as the crystallographic phase and morphology of the sample; and energy-dispersive X-ray spectrometry (EDS) and auger electron spectrometry (AES) to explore the sample’s homogeneity. As the photoconductive material’s properties were characterized, the CNSE research group found that the material is extremely resistant to contamination. Additionally, the team utilized a green LED to direct pulsed light at the nanosheets and found that they exhibited a reliable response to light and an excellent response time between 18 and 73 milliseconds, indicating that In2Se3 nanosheets could be a highly effective material for real-time imaging purposes.

The nanosheets were also tested for the ability to detect light and for light responsivity, or the ratio of generated photocurrent to incident light power. The researchers noted that the photoconductive response of the nanosheets, which had a thickness of 3.9 nanometers, was demonstrably higher than other 2D photoresistors across a broad light spectrum, including Ultraviolet, visible light, and infrared, making them suitable for use in a wide-range of imaging devices.

Here’s a link to and a citation for the paper,

Extraordinary Photoresponse in Two-Dimensional In2Se3 Nanosheets by Robin B. Jacobs-Gedrim, Mariyappan Shanmugam, Nikhil Jain, Christopher A. Durcan, Michael T. Murphy, Thomas M. Murray, Richard J. Matyi, Richard L. Moore, II, and Bin Yu.  ACS Nano (2014), vol. 8, no. 1, pp. 514-21

This is a PDF of the document and is being made available by the researchers and their institution.