NSF Award
2328869
Professors Franky So, Veena Misra, Margaret Blanchard and Kenan Gundogdu of North Carolina State University and Professor Wei You of University of North Carolina at Chapel Hill are supported by the NSF Future of Semiconductors (FuSe) Program to develop a co-design approach that involves materials, devices, and systems technology. Low bandgap conjugated polymers with response in the shortwave infrared (SWIR) region will be synthesized and used as polymeric photodiode sensors for infrared imaging applications. Current state-of-the-art SWIR imaging relies on sensors made from inorganic alloys, which are incompatible with CMOS chips and suffer from extremely high production costs and limited image resolution. The polymeric systems, which will be fabricated using processing techniques fully compatible with CMOS technology, are posed to deliver higher image resolution and performance at a much-reduced production cost. Success in developing a SWIR imaging systems will result in a paradigm shift in imaging systems that are not possible with currently available imaging technologies. The research team is collaborating with an industrial partner, SWIR Vision Systems, to demonstrate a low-cost SWIR prototype camera. In addition to advancing imaging technology, the project outcomes will be broadly impactful on other practical applications, including medical diagnostics, security, and communications. During the course of conducting the proposed research a diverse group of undergraduate students from North Carolina State University and local community colleges will be recruited as “FuSe Fellows” to be trained for future careers in microchip manufacturing. Additionally, a number of outreach activities geared towards local high schools, including lab tours and special demonstrations, will be conducted.<br/><br/>The goal of this project is to develop organic polymer-based photodiodes for short-wave infrared (SWIR) imaging applications. Current state-of-the-art SWIR imaging requires sensors made with InGaAs heterogeneously integrated with CMOS readout chips. While the current sensor is a proven technology, the incompatibility of InGaAs with silicon leads to high production costs and limited camera resolution. To mitigate these challenges, low-bandgap conjugated polymers will be used to fabricate photodiodes through simple solution processing and vacuum deposition. As the processing of these photodiode arrays is fully compatible with silicon in a standard silicon fabrication facility, heterogeneous integration of the resulting SWIR focal plane arrays with the silicon backplane will be straightforward. The project involves: 1) the design and synthesis of conjugated polymers with SWIR absorption bands; photophysical characterization of photocarrier generation and dynamics in single component and donor polymer/molecular acceptor systems; 3) photodiode design, fabrication and characterization of optical and electrical properties; 4) heterogeneous fabrication and characterization of devices compatible with Si backplane process and development of a process to fabricate focal plane array for SWIR camera prototypes; and DFT and ML computational calculations to inform the experiments.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
