Review of III-V Solar Cells: Fabrication, Applications and Development in Argentina

A.C. REYBET; J. PLÁ; P. GIUDICI

Bogotá

Workshop; 2nd. Latin American Workshop: Energy transition. Addressing Sustainable Development; 2019

Multi-junctionsolar cells based on III-V compounds, also called tandem solar cells, consistsof singles solar cells stacked upon each other, increasing the overallefficiency. III-V solar cells are made of multiple layers of differentcompounds using elements of columns III and V of the periodic table, forexample, Gallium Arsenide, Aluminum Gallium Phosphide or Indium GalliumArsenide. The efficiency of traditional silicon solar cells, at lab level, canarise 26.1%, whereas experimental measurements showed a 47.1% of energyconversion in III-V solar cells under concentration. Due to thehigh fabrication cost of III-V solar cells, the most common applications arefor space uses in satellites. The latest researches are focused, however, inIII-V solar cells for concentrating photovoltaics (CPV) for terrestrialapplication; the high efficiency of these systems makes them economicallycompetitive. CPV includes a system of lenses or reflectors to focus sunlight ona small area of solar cells, allowing the solar cell to generate more power.Using III-V solar cells in CPV strongly reduces the cost of the concentrationsystem and also decreases the surface of the solar installation.Themultilayers of the semiconductor devices are fabricated using the metalorganicchemical vapor deposition technique (MOCVD). The epitaxial MOCVD reactorsdeposit layer by layer, through a chemical reaction in vapor phase, a widevariety of desired compounds. The Solar Energy Department of CNEA in Argentinahas a long history in research and characterization of III-V solar cells, aswell as integration of power solar arrays for satellites, and recently hasacquired an MOCVD reactor. This reactor, the first in Argentina, brings a hugepotential to the national development in solar cells and it will allowreplacing commercial III-V solar cells, generally of very high cost, by othersof national technology.