skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current

Abstract

Here, we report the demonstration of dilute nitride heterostructure core/shell microwire solar cells utilizing the combination of top-down reactive-ion etching to create the cores (GaP) and molecular beam epitaxy to create the shells (GaNP). Systematic studies of cell performance over a series of microwire lengths, array periods, and microwire sidewall morphologies examined by transmission electron microscopy were conducted to shed light on performance-limiting factors and to optimize the cell efficiency. We also show by microscopy and correlated external quantum efficiency characterization that the open circuit voltage is degraded primarily due to the presence of defects at the GaP/GaNP interface and in the GaNP shells, and is not limited by surface recombination. Compared to thin film solar cells in the same growth run, the microwire solar cells exhibit greater short circuit current but poorer open circuit voltage due to greater light absorption and number of defects in the microwire structure, respectively. Finally, we present performance benefits of dilute nitride microwire solar cells and show that it can be achieved by further tuning of the epitaxial quality of the underlying materials.

Authors:
 [1];  [2];  [3];  [2];  [4];  [5];  [5]
  1. Univ. of California, San Diego, CA (United States). Graduate Program of Materials Science and Engineering
  2. Univ. of California, San Diego, CA (United States). Dept. of Electrical and Computer Engineering
  3. Univ. of California, La Jolla, CA (United States). Dept. of Electrical and Computer Engineering
  4. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies
  5. Univ. of California, San Diego, CA (United States). Graduate Program of Materials Science and Engineering and Dept. of Electrical and Computer Engineering
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
OSTI Identifier:
1340235
Report Number(s):
SAND2016-2940J
Journal ID: ISSN 0021-8979; 637544; TRN: US1701738
Grant/Contract Number:
AC04-94AL85000; AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 120; Journal Issue: 5; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY

Citation Formats

Sukrittanon, Supanee, Liu, Ren, Breeden, Michael C., Pan, Janet L., Jungjohann, K. L., Tu, Charles W., and Dayeh, Shadi A. Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current. United States: N. p., 2016. Web. doi:10.1063/1.4959821.
Sukrittanon, Supanee, Liu, Ren, Breeden, Michael C., Pan, Janet L., Jungjohann, K. L., Tu, Charles W., & Dayeh, Shadi A. Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current. United States. doi:10.1063/1.4959821.
Sukrittanon, Supanee, Liu, Ren, Breeden, Michael C., Pan, Janet L., Jungjohann, K. L., Tu, Charles W., and Dayeh, Shadi A. 2016. "Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current". United States. doi:10.1063/1.4959821. https://www.osti.gov/servlets/purl/1340235.
@article{osti_1340235,
title = {Radial direct bandgap p-i-n GaNP microwire solar cells with enhanced short circuit current},
author = {Sukrittanon, Supanee and Liu, Ren and Breeden, Michael C. and Pan, Janet L. and Jungjohann, K. L. and Tu, Charles W. and Dayeh, Shadi A.},
abstractNote = {Here, we report the demonstration of dilute nitride heterostructure core/shell microwire solar cells utilizing the combination of top-down reactive-ion etching to create the cores (GaP) and molecular beam epitaxy to create the shells (GaNP). Systematic studies of cell performance over a series of microwire lengths, array periods, and microwire sidewall morphologies examined by transmission electron microscopy were conducted to shed light on performance-limiting factors and to optimize the cell efficiency. We also show by microscopy and correlated external quantum efficiency characterization that the open circuit voltage is degraded primarily due to the presence of defects at the GaP/GaNP interface and in the GaNP shells, and is not limited by surface recombination. Compared to thin film solar cells in the same growth run, the microwire solar cells exhibit greater short circuit current but poorer open circuit voltage due to greater light absorption and number of defects in the microwire structure, respectively. Finally, we present performance benefits of dilute nitride microwire solar cells and show that it can be achieved by further tuning of the epitaxial quality of the underlying materials.},
doi = {10.1063/1.4959821},
journal = {Journal of Applied Physics},
number = 5,
volume = 120,
place = {United States},
year = 2016,
month = 8
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share:
  • We report the demonstration of dilute nitride heterostructure core/shell microwire solar cells utilizing the combination of top-down reactive-ion etching to create the cores (GaP) and molecular beam epitaxy to create the shells (GaNP). Systematic studies of cell performance over a series of microwire lengths, array periods, and microwire sidewall morphologies examined by transmission electron microscopy were conducted to shed light on performance-limiting factors and to optimize the cell efficiency. We show by microscopy and correlated external quantum efficiency characterization that the open circuit voltage is degraded primarily due to the presence of defects at the GaP/GaNP interface and in themore » GaNP shells, and is not limited by surface recombination. Compared to thin film solar cells in the same growth run, the microwire solar cells exhibit greater short circuit current but poorer open circuit voltage due to greater light absorption and number of defects in the microwire structure, respectively. The comprehensive understanding presented in this work suggests that performance benefits of dilute nitride microwire solar cells can be achieved by further tuning of the epitaxial quality of the underlying materials.« less
  • In this study, we demonstrate –2.05 eV dilute nitride GaNP solar cells on GaP substrates for potential use as the top junction in dual-junction integrated cells on Si. By adding a small amount of N into indirect-bandgap GaP, GaNP has several extremely important attributes: a direct-bandgap that is also tunable, and easily attained lattice-match with Si. Our best GaNP solar cell ([N] –1.8%, E g –2.05 eV) achieves an efficiency of 7.9%, even in the absence of a window layer. This GaNP solar cell's efficiency is 3× higher than the most efficient GaP solar cell to date and higher thanmore » other solar cells with similar direct bandgap (InGaP, GaAsP). Through a systematic study of the structural, electrical, and optical properties of the device, efficient broadband optical absorption and enhanced solar cell performance are demonstrated.« less