Abrupt dependence of ultrafast extrinsic photoconductivity on er fraction in gaas:er

Published

July 1, 2017

Author(s)

Elliott Brown, A. Mingardi, W-D. Zhang, Ari Feldman, Todd E. Harvey, Richard Mirin

Abstract

We present a study of room-temperature, ultrafast photoconductivity associated with strong, sub-bandgap, resonant absorption around lamba} = 1550 nm in three MBE-grown GaAs epitaxial layers heavily doped with Er at concentrations of ≅2.9 x 10¹⁸ (control sample), 4.4 x 10²⁰, and 8.8 x 10²⁰ cm^-3, respectively. Transmission-electron microscopy reveals a lack of nanoparticles in the control sample, but an abundance in the other two samples in the 1.0-to-3.0-nm-diameter range, consistent with the previously-known results. The novelty of the present work is demonstrating very high photoelectron (Hall) mobility (2.26x10³ cm²/V-s) and terahertz power (46 υW average) in the 4.4 x 10²⁰ sample, but then an abrupt decay in these properties as well as the dark resistivity as the Er doping is increased just 2 times. The Er doping has little effect on the picosecond-scale, 1550 nm photocarrier lifetime.

Citation

Applied Physics Letters

Issue

111

Pub Type

Journals

Download Paper

https://doi.org/10.1063/1.4991876

Local Download

Keywords

photoconductivity, rare-earth doped semiconductor, ultrafast materials

Citation

Brown, E. , Mingardi, A. , Zhang, W. , Feldman, A. , Harvey, T. and Mirin, R. (2017), Abrupt dependence of ultrafast extrinsic photoconductivity on er fraction in gaas:er, Applied Physics Letters, [online], https://doi.org/10.1063/1.4991876, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922945 (Accessed October 11, 2025)