Chapter 16 - Quantum Well Solar Cells and Quantum Dot Concentrators

Abstract

This chapter focusses on quantum well solar cells and quantum dot concentrators. This chapter reviews the development over the past half a decade of the quantum well solar cell (QWSC) and the quantum dot concentrator (QDC). The study of nanostructures such as quantum wells (QWs) and quantum dots (QDs) has dominated opto-electronic research and development for the past two decades. The chapter also reviews recent advances since then, concentrating in particular on studies of the strain-balanced quantum well solar cell (SB-QWSC) as a concentrator cell and the thermodynamic modelling of the QDC. The SB-QWSC offers a way to extend the spectral range of the highest efficiency single-junction cell, the GaAs cell. It discusses the way this can in principle lead to higher efficiency in both single-junction and multi-junction cells and offers particular advantages in high-concentration systems. The high efficiency, wide spectral range, and small cell size make these systems particularly attractive for high concentration, building-integrated applications using direct sunlight. The chapter also demonstrates a 3D thermodynamic model capable of describing the performance of dye-doped and QD-doped slabs of luminescent concentrators. The model is a powerful tool for analyzing the performance of the luminescent concentrators. The fits show that concentrator performance is currently limited by the quantum efficiency (QE) of the QDs dispersed in the plastics.