Photon Coupling Effects and Advanced Characterisations of Multiple-Quantum-Well Multi-Junction Solar Cells
File(s)
Author(s)
Lee, Kan-Hua
Type
Thesis
Abstract
Achieving optimal band-gap combinations of multi-junction solar cells at production level is the most difficult challenge in concentrator photovoltaics. To improve the state-of-the-art InGaP/InGaAs/Ge triple-junction cells, it requires that the band gaps of the top and middle junction to be lower or an additional 1 eV junction. This involves lattice-mismatch growth or introducing dilute nitrides materials, which makes it difficult to scale up to production at low cost. Strain-balanced multiple quantum wells (MQWs) in the middle junction has been very well-studied as a means to adjust the absorption edges of the middle junction in multi-junction solar cells. To fully optimise the efficiency of solar cells with MQW GaAs subcell, an InGaP top cell with MQWs also has to be introduced to achieve current-matching.
The aim of this thesis is to address the issues of production multi-junction cell with MQWs. We studied the material properties of MQW InGaP subcells and demonstrated its strong photon coupling effects in multi-junction devices. Several characterisation techniques were developed to acquire deeper understanding of the material qualities and sheet resistance of MQW solar cells.
The aim of this thesis is to address the issues of production multi-junction cell with MQWs. We studied the material properties of MQW InGaP subcells and demonstrated its strong photon coupling effects in multi-junction devices. Several characterisation techniques were developed to acquire deeper understanding of the material qualities and sheet resistance of MQW solar cells.
Version
Open Access
Date Issued
2014-01
Date Awarded
2014-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Ekins-Daukes, Nicholas
Stavrinou, Paul
Sponsor
QUANTASOL Ltd
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)