An Experimental Method to Directly Obtain a Photogenerated Current at Each Junction within the Triple Junction Solar Cell

TL;DR

This paper introduces an easy experimental method to directly measure the photogenerated current at each junction in triple junction solar cells using multiple current-voltage curves with different light spectra.

Contribution

It presents a novel, simple technique for directly determining individual junction currents in triple junction solar cells through simultaneous fitting of multiple I-V curves.

Findings

Method successfully applied to various TJ solar cells.

Allows direct measurement without complex disassembly.

Compatible with standard laboratory equipment.

Abstract

In this paper we will report an experimental approach for directly determining the photogenerated current at individual junctions within the triple junction solar cell. The method is based on the measurement of different current-voltage curves; one with the usual illumination system, normally AM0 or AM1.5G, and the other curves with a light source, having a different spectral emission. The fitting of all current-voltage curves simultaneously, not individually, permit us to determine the photogenerated current of three junctions. It is necessary to have three characteristics or more. An example, with experimental current-voltage data points, is shown in this work. The main advantage of this new technique is its simplicity and its easy implementation at any laboratory with an electrical characterization solar cell system and a solar simulator. The method has been tested over a large quantity of TJ solar cells.