Enhancing Solar Cells with Nanophotonics: Understanding and improving cell performance

People

Supervisor

Research areas

Description

Nanophotonic light trapping for solar cells can boost the absorption, reducing the thickness of the device that is needed to absorb a significant portion of the incident light.  Having thin semiconductor layers reduces the stringent requirements on material quality for optoelectronic applications, allowing materials with poorer charge transport properties to be used as the charge carriers have a shorter distance to travel before they are collected.  This has opened the door for new material systems with significantly reduced manufacturing costs, and the ability to fabricate devices on flexible substrates for next generation lightweight, integrated solar cells.

In general, nanophotonic light trapping does not only change how much light is absorbed, but also where in the solar cell this happens.  In high quality semiconductors photogenerated charge carriers are able to diffuse freely throughout the device, so that no matter where they are generated, they will redistribute themselves uniformly and be collected.  However, it is precisely the materials for which nanophotonic light trapping is particularly attractive - those with poorer charge transport properties – for which the assumption that carriers will be uniformly redistributed does not hold. 

Preliminary studies have shown that for diffusion lengths on the order of, or smaller than the width of the active semiconducting region non-uniform absorption can lead to a non-uniform photogenerated density distribution

The goal of this project is to determine and quantify the effect of non-uniform photogeneration on solar cell performance, especially with respect to the open circuit voltage, short circuit current, recombination, and internal collection efficiency. 

Suitable for: 12 unit courses for R&D students: ENGN 3712, 4712 and Honours project ENGN 4200

Goals

  1. Generate a range of realistic generation profiles in Matlab that would result from nanophotonic light trapping based on a literature survey.
  2. Use existing open source software (SCAPS) to model different photovoltaic devices and study their carrier transport and collection properties in the presence of non-uniform generation profiles.
  3. Compare device performance under uniform and non-uniform generation and quantify the effect on the figure of merit of the solar cells.
  4.  Investigate the possibility of boosting solar cell performance by modifying the generation profile.
  5. Understand and discuss the opportunities and limitations of numerical modelling method.

Requirements

This is a computer based modelling project, suitable for students with an interest in solar cells, optical devices and optoelectronics.  It would be particularly good experience for anyone interested in a research career, or in R&D in the area of semiconductor devices or solar cells.  Background knowledge of the fundamentals of semiconductors is important.  Interest in Matlab and numerical (FEM) modelling is essential; competency in modelling is useful.  The ability to think logically and creatively solve problems will be required.

Prerequisite: ENGN3334 (Semiconductors) or ENGN3512 (Optical Physics)

Suitable for: 12 unit courses for R&D students: ENGN 3712, 4712 and Honours project ENGN 4200

Gain

Over the course of the project you will:

  • Engage with a novel research problem
  • Develop a deeper understanding of semiconductor physics and how solar cells operate
  • Gain experience in solar cell device modelling
  • Have hands on experience of the limits and opportunities of numerical modelling
  • Get a chance to independently and creatively solve problems
  • Undertake independent research and build up your analytical skills
  • Project manage

Keywords

Semiconductors, Optoelectronics, Photovoltaics, Solar Energy, Solar Cells, Optical Devices, Nanophotonics, Nanostructures, Modelling

Updated:  8 September 2015/Responsible Officer:  Head of School/Page Contact:  CECS Marketing