Sub-millisecond response time in a photorefractive composite operating under CW conditions

Journal Article · Thu Sep 01 00:00:00 EDT 2016 · Scientific Reports

DOI:https://doi.org/10.1038/srep30810· OSTI ID:1323899

Moon, Jong -Sik ^[1]; Stevens, Tyler E. ^[2]; Monson, Todd C. ^[2]; Huber, Dale L. ^[2]; Jin, Sung -Ho ^[3]; Oh, Jin -Woo ^[3]; Winiarz, Jeffrey G. ^[4]

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1. Missouri Univ. of Science and Technology, Rolla, MO (United States); Pusan National Univ., Busan (Korea)
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
3. Pusan National Univ., Busan (Korea)
4. Missouri Univ. of Science and Technology, Rolla, MO (United States)

Extensive study of photorefractive polymeric composites photosensitized with semiconductor nanocrystals has yielded data indicating that the inclusion of such nanocrystals enhances the charge-carrier mobility, and subsequently leads to a reduction in the photorefractive response time. Unfortunately, the included nanocrystals may also act as a source of deep traps, resulting in diminished diffraction efficiencies as well as reduced two beam coupling gain coefficients. Nonetheless, previous studies indicate that this problem is mitigated through the inclusion of semiconductor nanocrystals possessing a relatively narrow band-gap. Here, we fully exploit this property by doping PbS nanocrystals into a newly formulated photorefractive composite based on molecular triphenyldiamine photosensitized with C₆₀. Through this approach, response times of 399 μs are observed, opening the door for video and other high-speed applications. It is further demonstrated that this improvement in response time occurs with little sacrifice in photorefractive efficiency, with internal diffraction efficiencies of 72% and two-beam-coupling gain coefficients of 500 cm^–1 being measured. A thorough analysis of the experimental data is presented, supporting the hypothesized mechanism of enhanced charge mobility without the accompaniment of superfluous traps. As a result, it is anticipated that this approach can play a significant role in the eventual commercialization of this class of materials.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1323899
• Report Number(s): SAND2016-8655J; 647132
• Journal Information: Scientific Reports, Vol. 6; ISSN 2045-2322
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE