Ultrafast Broadband Photodetectors for High-Tc Superconductive Optoelectronics
Abstract
Experimental research has been conducted to demonstrate the potential of the high-temperature superconductors (HTS) for optoelectronics. We performed systematic characterization of femtosecond optical response of superconducting YBa2Cu3O(x) (YBCO) thin films. We measured, for the first time, 1.5-ps-wide photoresponse signals from an epitaxial YBCO film irradiated with 150 fs optical pulses. Our results shed new light on the nonequilibrium carrier dynamics in HTS, as well as convincingly demonstrated that these materials are suitable for ultrahigh speed optoelectronic applications. We have developed a new, laser-based processing technique (so-called laser writing) for fabrication of HTS optoelectronic devices. The method exploited the contrasting optical and electrical properties of the oxygen-poor (semiconducting) and oxygen-rich (superconducting) YBCO phases and was used to fabricate superconducting structures with various oxygen doping profiles and YBCO photodetectors. Optical measurements were supplemented by extensive transport experiments of both partially oxygen-depleted and photodoped YBCO films. We observed both the persistent and erasable changes of the normal-state transport and superconducting properties of YBCO films, exposed to a prolonged white-light illumination at low temperatures. Our results indicated that both the charge transfer and oxygen ordering mechanisms were responsible for the photoinduced effects in YBCO.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADA344891
Entities
People
- Philippe M. Fauchet
- Roman Sobolewski
Organizations
- University of Rochester