Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

Transparent Conductors Based on Microscale/Nanoscale Materials for High Performance Devices

Gao, Tongchuan (2017) Transparent Conductors Based on Microscale/Nanoscale Materials for High Performance Devices. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

This is the latest version of this item.

[img]
Preview
PDF
Download (11MB) | Preview

Abstract

Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), flat panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell’s equations and Poisson’s equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 Ω/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short-circuit current-density was demonstrated by the optimal solar cell compared with 300-nm-thick Si solar cell with antireflection coating and silver back reflector.


Share

Citation/Export:
Social Networking:
Share |

Details

Item Type: University of Pittsburgh ETD
Status: Unpublished
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Gao, Tongchuantog8@pitt.eduTOG80000-0003-4800-3641
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairLeu, Paulpleu@pitt.edu
Committee MemberBidanda, Bopayabidanda@pitt.edu
Committee MemberLee, Jung-kunjul37@pitt.edu
Committee MemberChun, Youngjaeyjchun@pitt.edu
Date: 1 February 2017
Date Type: Publication
Defense Date: 31 August 2016
Approval Date: 1 February 2017
Submission Date: 3 September 2016
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 131
Institution: University of Pittsburgh
Schools and Programs: Swanson School of Engineering > Industrial Engineering
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: transparent conductors, solar cells, photovoltaics, nanomaterials, graphene
Date Deposited: 01 Feb 2017 20:27
Last Modified: 02 Feb 2017 06:15
URI: http://d-scholarship.pitt.edu/id/eprint/30035

Available Versions of this Item

  • Transparent Conductors Based on Microscale/Nanoscale Materials for High Performance Devices. (deposited 01 Feb 2017 20:27) [Currently Displayed]

Metrics

Monthly Views for the past 3 years

Plum Analytics


Actions (login required)

View Item View Item