Adrien and Abhinav’s paper on organic phototransistors got published in Nature Photonics

Paper title: Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors

Abstract: Solution-processed phototransistors can substantially advance the performance of image sensors. Phototransistors exhibit large photoconductive gain and a sublinear responsivity to irradiance, which enables a logarithmic sensing of irradiance that is akin to the human eye and has a wider dynamic range than photodiode-based image sensors. Here, we present a novel solution-processed phototransistor composed of a heterostructure between a high-mobility organic semiconductor and an organic bulk heterojunction. The device efficiently integrates photogenerated charge during the period of a video frame then quickly discharges it, which significantly increases the signal-to-noise ratio compared with sampling photocurrent during readout. Phototransistor-based image sensors processed without photolithography on plastic substrates integrate charge with external quantum efficiencies above 100\% at 100 frames per second. In addition, the sublinear responsivity to irradiance of these devices enables a wide dynamic range of 103 dB at 30 frames per second, which is competitive with state-of-the-art image sensors.

Publication:

1. 
   Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors Adrien Pierre, Abhinav Gaikwad, and Ana Claudia Arias Nature Photonics, 2017 [Abstract] [Bibtex] [PDF] Article

   Solution-processed phototransistors can substantially advance the performance of image sensors. Phototransistors exhibit large photoconductive gain and a sublinear responsivity to irradiance, which enables a logarithmic sensing of irradiance that is akin to the human eye and has a wider dynamic range than photodiode-based image sensors. Here, we present a novel solution-processed phototransistor composed of a heterostructure between a high-mobility organic semiconductor and an organic bulk heterojunction. The device efficiently integrates photogenerated charge during the period of a video frame then quickly discharges it, which significantly increases the signal-to-noise ratio compared with sampling photocurrent during readout. Phototransistor-based image sensors processed without photolithography on plastic substrates integrate charge with external quantum efficiencies above 100% at 100 frames per second. In addition, the sublinear responsivity to irradiance of these devices enables a wide dynamic range of 103 dB at 30 frames per second, which is competitive with state-of-the-art image sensors.

   @article{pierre2017charge, author = {Pierre, Adrien and Gaikwad, Abhinav and Arias, Ana Claudia}, title = {Charge-integrating organic heterojunction phototransistors for wide-dynamic-range image sensors}, journal = {Nature Photonics}, year = {2017}, month = feb, day = {20}, publisher = {Nature Publishing Group}, note = {Article}, issn = {1749-4893}, url = {http://dx.doi.org/10.1038/nphoton.2017.15}, thumbnail = {pierre2017charge.png}, pdf = {pierre2017charge.pdf} }