High Efficiency Multijunction Photovoltaic Development

Abstract

Photovoltaic energy conversion has demonstrated remarkable improvements in performance over the past 60 years. The rate of solar cell efficiency change has actually increased over the past 20 years as researchers have moved beyond elemental semiconductors to increasingly more sophisticated materials and devices. In addition, significant improvements in materials quality and deposition technology have further fueled this dramatic improvement in device performance. Diversifying from silicon to III−V compound semiconductor materials has enabled the development of multijunction solar cells with 3, 4, and even 6 subcells to achieve ever higher conversion efficiency. For 1-sun space application(s), these III−V multijunction cells are demonstrating ∼35% efficiency, while under terrestrial concentrated sunlight conditions efficiencies are >42%. This Article will discuss the development of high efficiency III−V multijunction solar cells, focusing on recently developed metamorphic device structures and novel lattice matched approaches.

Quadrupolar (donor)2acceptor-acid chromophores for dye-sensitized solar cells: influence of the core acceptor

“…Starting compounds 1, 11 2b, 12 4, 9 6 13 and 8 14 were synthesized as described in the literature. 1 H and 13 C NMR spectra were collected on a Mercury 300, Gemini 300, Bruker 400 or on an Inova 500. Chemical shis were referenced to the residual solvent peaks.…”

“…Inorganic based solar cells can reach efficiencies above 30% but the high temperatures and the strong vacuum required during manufacturing represent a large disadvantage. 1 Organic solar cells are valuable in terms of processability, exibility and aesthetics; 2 however the "promised land" of commercially-protable efficiency (PCE > 15%) has not yet been reached. Developed in 1991 by O'Regan and Grätzel, 3 dye-sensitized solar cells (DSSCs) are a hybrid system composed of metal complex or p-conjugated organic dyes adsorbed onto mesoporous titanium dioxide (TiO 2 ) lms.…”

Electron Irradiation Effects and Defects Analysis of the Upright Metamorphic Four‐Junction (UMM4J) Solar Cells

“…[ 9 ] The thermalization loss can be reduced by adding additional junctions to increase the range of solar spectrum. [ 10 ] The addition of additional junctions has been realized via inverted metamorphic multijunction (IMM) strategy. The highest conversation efficiency of IMM6J solar cell based on the inverted epitaxial growth and substrate transfer is as high as 37% (AM0 1sun) [ 11,12 ] and that of IMM4J is as high as 35.3% (AM0 1sun).…”

Multijunction Concentrator Solar Cells: Analysis and Fundamentals

“…The stacked-subcell approach has resulted in MJ cells of >40 % solar conversion efficiency [6][7][8]. Further work includes quantum well and quantum dot layers as well as inverted metamorphic (IMM) TJ solar cells [1,9]. Combinations of GaAs and GaSb have also shown promise [5].…”