Optical coupling from InGaAs subcell to InGaP subcell in InGaP/InGaAs/Ge multi-junction solar cells

Abstract

Spatially-resolved electroluminescence (EL) images in the triple-junction InGaP/InGaAs/Ge solar cell have been investigated to demonstrate the subcell coupling effect. Upon irradiating the infrared light with an energy below bandgap of the active layer in the top subcell, but above that in the middle subcell, the EL of the top subcell quenches. By analysis of EL intensity as a function of irradiation level, it is found that the coupled p-n junction structure and the photovoltaic effect are responsible for the observed EL quenching. With optical coupling and photoswitching effects in the multi-junction diode, a concept of infrared image sensors is proposed.

A-Crater-within-a-Crater Approach for Secondary Ion Mass Spectrometry Evaluation of the Quality of Interfaces of Multilayer Devices

“…In this work, we test such a procedure on a triple-junction solar cell structurea device of great importance, as solar energy is considered to be one of the key energy resources with most commonly mentioned benefits like availability, reliability, and cleanliness. Working principle of multijunction solar cells is well discussed in the literature. − Briefly, they are composed of several different p–n junctions that produce electric current in response to different wavelengths of light. In this way, a broader range of solar spectrum can be absorbed and thus the energy conversion efficiency is increased.…”

Frequency response of the external quantum efficiency in multijunction solar cells

“…A suite of opto-electronic characterization techniques has been used in the past to explore the various characteristics of these cells. Extensive light bias and voltage bias dependent external quantum efficiency measurements [3–10], detailed current-voltage (I–V) characterization [11], and electroluminescence measurements [12,13] have traditionally been used to elucidate various artifacts and phenomena such as low shunt resistance effects [3,6,7,9,14,15], reverse breakdown voltage [3,4,16], and luminescence coupling (LC) [10,11,17–21] in these devices. Furthermore, new techniques such as electric modulus spectroscopy [22] have been used to observe charge coupling effects in Ge-based triple junction solar cells.…”

Light management of a-SiOx:H thin film solar cells with hydrogen-reduced p+ buffer at TiO2/p-layer interface

“…Multi-junction structures have been a promising solution for improving efficiency of thin film solar cells in terms of efficient utilization of solar spectrum [1][2][3][4][5][6][7]. Recently, multi-junction cells with mechanically stacked structure have been widely developed for high efficiency, and triple [2,6,8,9] or quadruple [5] junction cells are the recent advanced versions of the multi-junction cells reported in those studies.…”

“…Recently, multi-junction cells with mechanically stacked structure have been widely developed for high efficiency, and triple [2,6,8,9] or quadruple [5] junction cells are the recent advanced versions of the multi-junction cells reported in those studies. In the view of these trends, we developed full-spectrum 4-terminal thin film solar cell consisting of hydrogenated amorphous silicon (a-Si:H) top cell and CuInGaSe 2 bottom cell using optical splitters [10].…”