Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Sakshi Gupta - Thesis - July 03 (v1).pdf (36.99 MB)

Digital Accessibility Report

File List


Sakshi Gupta - Thesis - July 03 (v1).pdf.accreport.html (7.92 KB)

ETD Abstract Container

Abstract Header

Investigating the impact of Bulk and Surface Recombination on Open-circuit Voltage in Thin-film Cd(Se,Te) Photovoltaic devices: A Computational approach

Gupta, Sakshi
http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1720023685824664

Abstract Details

2024, Master of Science (MS), Bowling Green State University, Physics.
Cd(Se,Te) has emerged as a leading choice for commercial thin-film PV devices, owing to their lower cost of production, high energy yields, and low degradation rates compared to silicon technology. Despite significant advancements, Cd(Se,Te) cells suffer from recombination losses, reducing the open-circuit voltage (Voc). This thesis aims to identify, distinguish, and quantify recombination losses and their locations within Cd(Se,Te) solar cells via temperature and light intensity-dependent current-voltage (JVTi) analysis. Cd(Se,Te) solar cells were modeled using COMSOL Multiphysics, simulating parameters such as temperature (T ), light intensity (i), front surface recombination velocity (Sf), back surface recombination velocity (Sb), bulk lifetime (τ ), conduction and valence band offset (CBO and VBO at heterojunctions), and back contact Schottky barrier height (Φbp). Additionally, graded and uniform selenium devices were studied, and ZnTe:Cu was investigated as a back contact interface. In this work, recombination activation energies, Ea, from JVTi studies were shown to quantify the front interface conduction band offset losses when the interface band gap is smaller than the bulk band gap and when front interface recombination dominates. If the Ea equals the bulk band gap, then Voc losses may occur at the front interface or within the bulk. When the front surface recombination and bulk lifetime are moderately low, a transition from front surface (low Ea) to bulk (higher Ea) mechanisms can be observed with increasing light intensity, i. Back surface recombination has negligible effects on Voc for the device parameters specified herein. Comparison of Cd(Se,Te) JVTi data provided by NREL to simulations in this work indicates that front surface recombination dominates Voc losses for Sf = 103 cm/s and CBO = -0.2 eV for that particular device. Adjusting the band alignment to CBO = 0 eV and reducing Sf would significantly increase Voc.
Marco Nardone (Committee Chair)
Mikhail Zamkov (Committee Member)
Alexy Zayak (Committee Member)
87 p.
Physics
Thin-film PV; open circuit voltage; recombination; computational physics; Cd(Se,Te); activation energy; ZnTe:Cu back contact interface; buffer layer, JVTi

Recommended Citations

Citations

  • Gupta, S. (2024). Investigating the impact of Bulk and Surface Recombination on Open-circuit Voltage in Thin-film Cd(Se,Te) Photovoltaic devices: A Computational approach [Master's thesis, Bowling Green State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1720023685824664

    APA Style (7th edition)

  • Gupta, Sakshi. Investigating the impact of Bulk and Surface Recombination on Open-circuit Voltage in Thin-film Cd(Se,Te) Photovoltaic devices: A Computational approach. 2024. Bowling Green State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1720023685824664.

    MLA Style (8th edition)

  • Gupta, Sakshi. "Investigating the impact of Bulk and Surface Recombination on Open-circuit Voltage in Thin-film Cd(Se,Te) Photovoltaic devices: A Computational approach." Master's thesis, Bowling Green State University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1720023685824664

    Chicago Manual of Style (17th edition)

bgsu1720023685824664
79
© 2024, all rights reserved.
This open access ETD is published by Bowling Green State University and OhioLINK.