Diode Characteristics Approaching Bulk Limits in GaAs Nanowire Array Photodetectors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28334536.
- Also identified by DOI 10.1021/acs.nanolett.7b00024.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
We present the electrical properties of p-n junction photodetectors comprised of vertically oriented p-GaAs nanowire arrays on the n-GaAs substrate. We measure an ideality factor as low as n = 1.0 and a rectification ratio >10<sup>8</sup> across all devices, with some >10<sup>9</sup>, comparable to the best GaAs thin film photodetectors. An analysis of the Arrhenius plot of the saturation current yields an activation energy of 690 meV-approximately half the bandgap of GaAs-indicating generation-recombination current from midgap states is the primary contributor to the leakage current at low bias. Using fully three-dimensional electrical simulations, we explain the lack of a recombination current dominated regime at low forward bias, as well as some of the issues related to analysis of the capacitance-voltage characteristics of nanowire devices. This work demonstrates that, through proper design and fabrication, nanowire-based devices can perform as well as their bulk device counterparts.