Chapter 8: Light Capture

The efficient capture of light is an essential factor for consideration in all solar cell designs. This chapter explores antireflective and light trapping schemes designed to reduce optical losses in solar cells with the aim of improving device efficiency. After a survey of the different mechanisms available for antireflection and light trapping, the various schemes employing these mechanisms are described. This begins with the traditional methods of thin film antireflective coatings and large (micron) scale texturing before moving onto more recent developments in the use of subwavelength texturing, taking inspiration from natural ‘moth-eye’ antireflective surfaces. Finally, the rapidly emerging field of plasmonics for photovoltaics is explored in which metal nanoparticles scatter incoming light through the generation of localized surface plasmons. In each section, the simulation techniques used for design optimization are introduced and methods for experimental realization and implementation in a range of photovoltaic devices are described. The associated increases in cost and complexity conferred to the solar cell fabrication process are also considered because these are the main hindrances to wide scale adoption of new strategies of light capture.