An ultra-fast and flexible silicon phototransistor was created at the University of Wisconsin-Madison by electrical engineers. It can dramatically increase the performance of digital cameras. Researchers claim that their silicon phototransistor has the highest speed and responsiveness ever produced. Their new invention is likely to be a significant benefit for electronic light sensor-based products. The phototransistor can be integrated into digital cameras lenses to reduce bulkiness, improve acquisition speed, and even enhance the quality of still photos or videos. The phototransistor’s flexibility is unmatched and it responds faster than other phototransistors in the world. (Image: http://news.wisc.edu) Jung-Hun Seo, a research scientist, and Zhenqiang “Jack” Ma, professor of electrical and computer engineering, say the high-performance phototransistor far and away exceeds every single previous flexible phototransistor parameter, including response time and sensitivity. Details of the research by Prof. Seo, along with his colleagues were published in Advanced Optical Materials. The phototransistors convert light data to zeros and ones. As our eyes see, they sense light and then convert it into electrical charges proportional its wavelength and intensities. The electrical impulses that transmit an image to the brain are used for animals and humans. In digital cameras that use an electrical charge to create digital images, the string becomes a series of zeros. Although most phototransistors have a flat surface, they are rigidly constructed. The ones created by scientists, however, are flexible. They can mimic the mammalian eyes more effectively. Professor Ma stated that the curve can be made into any shape to suit the optical system. There is currently no simple way to achieve this. One key aspect to the success of new phototransistors is their innovative flip-transfer fabrication process. In which the final step is inverting the phototransistor onto an underlying plastic substrate. A reflective layer of metal is placed on the bottom at this point. Professor Ma stated that this arrangement has a higher efficiency in light absorption. Professor Ma stated that the system has a built in capability of sensing weak light. Professor Ma’s work was also supported by the U.S. Air Force. He added that “This demonstration shows great promise in high-performance, flexible photodetection system.” This demonstration demonstrates the ability to high-sensitivity photodetection as well as stable performance in bending conditions. These capabilities have not been seen before.” A Abstract was published by the journal. The authors stated that the flexible phototransistors’ capabilities of stable performance and high sensitivity light detection offer huge potential for flexible optical sensor applications. They are patenting their technology through Wisconsin Alumni Research Foundation. Citation: Flexible Phototransistors Based On Single-Crystalline silicon Nanomembranes Seo, J.H. Zhang, K. Kim, M. Zhao, D. Yang, H. Zhou, W. Ma, Z. Advanced Optical Materials. 26th October, 2015. DOI: 10.1002/adom. 201500402.
Digital camera performance may be improved by a super-fast phototransistor
