Latest Publications

Single Nanowire Photoconductive Terahertz Detectors Peng et al. Nano Lett., 15:206-210 (Jan 2015) [ pdf ][ DOI:10.1021/nl5033843 ] We have developed a phase sensitive detector of coherent THz radiation based on a single nanowire. The device uses one GaAs/AlGaAs core-shell nanowire as is active component.	Modulation Doping of GaAs/AlGaAs Core–Shell Nanowires With Effective Defect Passivation and High Electron Mobility Boland et al. Nano Lett., 15:1336-1342 (Jan 2015) [ pdf ][ DOI:10.1021/nl504566t ] We demonstrate effective modulation doping in GaAs nanowires. n-doping results in very long photoconductivity and PL lifetimes of 3.9ns and 2.4ns, in these nanowires.	Ultrafast Transient Terahertz Conductivity of Monolayer MoS2 and WSe2 Grown by Chemical Vapor Deposition Docherty et al. ACS Nano, 8:11147-11153 (Nov 2014) [ pdf ][ DOI:10.1021/nn5034746 ] We show that the photoconductivity and photoluminescence response time of just 350 fs from CVD-grown monolayer MoS2, and 1 ps from trilayer MoS2 and monolayer WSe2. Our results indicate the potential of these materials as high-speed optoelectronic materials.
Solution deposition-conversion for planar heterojunction mixed halide perovskite solar cells Docampo et al. Adv. Energy Mater., 4:1400355 (Oct 2014) [ pdf ][ DOI:10.1002/aenm.201400355 ] We present planar, fully solution-processed heterojunction mixed halide solar cells based on the solution deposition-conversion technique.	Electron Mobilities Approaching Bulk Limits in “Surface-Free” GaAs Nanowires Joyce et al. Nano Lett., 14:5989-5994 (Sep 2014) [ pdf ][ DOI:10.1021/nl503043p ] We demonstrate that engineering the GaAs nanowire surface by overcoating with optimized AlGaAs shells is an effective means of obtaining exceptionally high carrier mobilities and lifetimes.	Charge carrier recombination channels in the low-temperature phase of organic-inorganic lead halide perovskite thin films Wehrenfennig et al. APL Mater., 2:081513 (Aug 2014) [ pdf ][ DOI:10.1063/1.4891595 ] we present a temperature-dependent study of optical absorption and photoluminescence (PL) emission of vapor-deposited organic-inorganic Perovskite semiconductors exploring the nature of recombination channels in the room- and the low-temperature phase of the material.