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Title: High-efficiency Thin-film Fe 2SiS 4 and Fe 2GeS 4-based Solar Cells Prepared from Low-Cost Solution Precursors. Final Report

Abstract

The project aimed to provide solar energy education to students from underrepresented groups and to develop a novel, nano-scale approach, in utilizing Fe 2SiS 4 and Fe 2GeS 4 materials as precursors to the absorber layer in photovoltaic thin-film devices. The objectives of the project were as follows: 1. Develop and implement one solar-related course at Delaware State University and train two graduate students in solar research. 2. Fabricate and characterize high-efficiency (larger than 7%) Fe 2SiS 4 and Fe 2GeS 4-based solar devices. The project has been successful in both the educational components, implementing the solar course at DSU as well as in developing multiple routes to prepare the Fe 2GeS 4 with high purity and in large quantities. The project did not meet the efficiency objective, however, a functional solar device was demonstrated.

Authors:
ORCiD logo [1];  [2];  [2];  [3];  [4]
  1. Delaware State Univ., Dover, DE (United States); Univ. of Delaware, Newark, DE (United States)
  2. Delaware State Univ., Dover, DE (United States)
  3. Rowan Univ., Glassboro, NJ (United States)
  4. Univ. of Delaware, Newark, DE (United States). Inst. of Energy Conversion (IEC)
Publication Date:
Research Org.:
Delaware State Univ., Dover, DE (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Contributing Org.:
University of Delaware
OSTI Identifier:
1415038
Report Number(s):
DOE-DSU-6322-1
DOE Contract Number:
EE0006322
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; iron chalcogenides; thin-film PV; photovoltaics; solution-processed PV absorber; dye-sensitized solar cell

Citation Formats

Radu, Daniela Rodica, Liu, Mimi, Hwang, Po-yu, Berg, Dominik, and Dobson, Kevin. High-efficiency Thin-film Fe2SiS4 and Fe2GeS4-based Solar Cells Prepared from Low-Cost Solution Precursors. Final Report. United States: N. p., 2017. Web. doi:10.2172/1415038.
Radu, Daniela Rodica, Liu, Mimi, Hwang, Po-yu, Berg, Dominik, & Dobson, Kevin. High-efficiency Thin-film Fe2SiS4 and Fe2GeS4-based Solar Cells Prepared from Low-Cost Solution Precursors. Final Report. United States. doi:10.2172/1415038.
Radu, Daniela Rodica, Liu, Mimi, Hwang, Po-yu, Berg, Dominik, and Dobson, Kevin. Thu . "High-efficiency Thin-film Fe2SiS4 and Fe2GeS4-based Solar Cells Prepared from Low-Cost Solution Precursors. Final Report". United States. doi:10.2172/1415038. https://www.osti.gov/servlets/purl/1415038.
@article{osti_1415038,
title = {High-efficiency Thin-film Fe2SiS4 and Fe2GeS4-based Solar Cells Prepared from Low-Cost Solution Precursors. Final Report},
author = {Radu, Daniela Rodica and Liu, Mimi and Hwang, Po-yu and Berg, Dominik and Dobson, Kevin},
abstractNote = {The project aimed to provide solar energy education to students from underrepresented groups and to develop a novel, nano-scale approach, in utilizing Fe2SiS4 and Fe2GeS4 materials as precursors to the absorber layer in photovoltaic thin-film devices. The objectives of the project were as follows: 1. Develop and implement one solar-related course at Delaware State University and train two graduate students in solar research. 2. Fabricate and characterize high-efficiency (larger than 7%) Fe2SiS4 and Fe2GeS4-based solar devices. The project has been successful in both the educational components, implementing the solar course at DSU as well as in developing multiple routes to prepare the Fe2GeS4 with high purity and in large quantities. The project did not meet the efficiency objective, however, a functional solar device was demonstrated.},
doi = {10.2172/1415038},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 28 00:00:00 EST 2017},
month = {Thu Dec 28 00:00:00 EST 2017}
}

Technical Report:

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  • Fe 2SiS 4 and Fe 2GeS 4 crystalline materials posses direct bandgaps of ~1.55 and ~1.4 eV respectively and an absorption coefficient larger than 10^5 cm–1; their theoretical potential as solar photovoltaic absorbers has been demonstrated. However, no solar devices that employ either Fe 2SiS 4 or Fe 2GeS 4 have been reported to date. In the presented work, nanoprecursors to Fe 2SiS 4 and Fe 2GeS 4 have been fabricated and employed to build ultra-thin-film layers via spray coating and rod coating methods. Temperature-dependent X-Ray diffraction analyses of nanoprecursors coatings show an unprecedented low temperature for forming crystalline Femore » 2SiS 4 and Fe 2GeS 4. Fabricating of ultra-thin-film photovoltaic devices utilizing Fe 2SiS 4 and Fe 2GeS 4 as solar absorber material is presented.« less
  • A two-junction, monolithic, optically and electrically coupled solar cell has been designed and a successful prototype produced. Each junction is a thin-film polycrystalline cell, namely, CuInSe/sub 2//(CdZn)S and CdTe/(CdZn)S. All active semi-conductor layers are produced by physical vapor deposition. During this contract year, a procedure for producing thin-film p-type CdTe by physical vapor deposition and a usable transparent interconnect for the tandem cell were developed.
  • The long-term objective of this research was to obtain a stable, thin-film solar cell based on polycrystalline materials with an efficiency of 15%. The approach was to make a tandem cell based on CuInSe/sub 2//CdS as the bottom cell and CdTe/CdS as the top cell. An essential feature was to develop a CdTe cell with transport contacts. A suitable contacting system was developed using transparent conducting oxides (ITO and SnO/sub 2/) in conjunction with a thin layer of copper. Cells were made with efficiencies over 8.5%. A reproducible fabrication process for CuInSe/sub 2//(CdZn)S cells was developed based on CuInSe/sub 2/more » films grown by vacuum evaporation using Knudsen-type effusion sources. These cells were made with efficiencies over 10%. The composition of the CuInSe/sub 2/ films can be varied over a considerable range and still yield high-efficiency cells. Adding Zn to the CdS did not increase the V/sub oc/ of the devices; analysis showed that the V/sub oc/ is not controlled by interface recombination. The effect of oxidizing and reducing heat treatments on CuInSe/sub 2/ cells is to change carrier concentration and thus V/sub oc/. Analysis suggests that J/sub o/ is controlled by band-to-band recombination. Monolithic tandem CuInSe/sub 2/ CdTe cells have been made with efficiencies of approx.3%, demonstrating the feasibility of this approach. 33 refs., 36 figs., 37 tabs.« less
  • The authors have fabricated high-efficiency thin-film CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2} (CIGS)-based photovoltaic devices from solution-based electroplated (EP) and auto-plated (AP) precursors. As-deposited precursors are Cu-rich CIGS. Compositions were adjusted to CuIn{sub 1{minus}x}Ga{sub x}Se{sub 2} with additional In and Ga by physical vapor deposition (PVD) to the EP and AP precursor films. Auger analysis and grazing incident X-ray diffraction (GIXRD) were performed on devices prepared from EP and AP precursor films. The authors have also analyzed and compared EP, AP, and an PVD CIGS device by deep-level transient spectroscopy (DLTS).