Submitted on May 22, 2009
Accepted on July 28, 2009
High-Detectivity Polymer Photodetectors with Spectral Response from 300 nm to 1450 nm
Xiong Gong 1*, Minghong Tong 2, Yangjun Xia 3, Wanzhu Cai 3, Ji Sun Moon 2, Yong Cao 3*, Gang Yu 4, Chan-Long Shieh 4, Boo Nilsson 4, Alan J. Heeger 1*
1 Center of Polymers and Organic Solids, University of California, Santa Barbara, CA 93106, USA.; CBrite Inc., Goleta, CA 93117, USA.
2 Center of Polymers and Organic Solids, University of California, Santa Barbara, CA 93106, USA.
3 Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China.
4 CBrite Inc., Goleta, CA 93117, USA.
* To whom correspondence should be addressed.
Xiong Gong , E-mail: xgong{at}physics.ucsb.edu
Yong Cao , E-mail: poycao{at}scut.edu.cn
Alan J. Heeger , E-mail: ajhe{at}physics.ucsb.edu
Sensing from the ultraviolet-visible to the infrared is critical for a variety of industrial and scientific applications. Today, GaN-, Si-, and InGaAs-based detectors are used for different subbands within the ultraviolet to near-infrared wavelength range. We demonstrate polymer photodetectors with broad spectral response (300 nm to 1450 nm) fabricated by using a small-band-gap semiconducting polymer blended with a fullerene derivative. Operating at room temperature, the polymer photodetectors exhibit detectivities greater than 1012 cm Hz1/2/W and linear dynamic range over 100 dB. The self-assembled nanomorphology and device architecture result in high photodetectivity over this remarkably wide spectral range and reduce the dark current (and noise) to values well below dark currents obtained in narrow-band photodetectors made with inorganic semiconductors.
