INVESTIGATION OF PHOTOELECTRIC CONVERTERS WITH A BASE CADMIUM TELLURIDE LAYER WITH A DECREASE IN ITS THICKNESS FOR TANDEM AND TWO-SIDED SENSITIVE INSTRUMENT STRUCTURES

Natalya Deyneko,Roman Shevchenko,Igor Kryvulkin,Olexandr Tarasenko,Anastasiia Khmyrova,Mykola Matiushenko,Igor Khmyrov

doi:10.21303/2461-4262.2019.001002

Abstract

Photovoltaic cells with a base layer of cadmium telluride with a decrease in its thickness are studied. It is known that the widespread use of photovoltaic converters is constrained by their high price in the case of highly efficient instrument structures, or low efficiency. The creation of tandem and two-sided sensitive photoelectric converters will reduce their cost while increasing their efficiency. However, to create tandem and two-sided sensitive photoelectric converters, the necessary conditions are the use of transparent contacts and a decrease in the thickness of the base layer for efficient absorption of incident radiation by the converter, which is lower. In the research process, it was found that reducing the thickness of the base layer to 1 μm allows to increase the efficiency of the photoelectric transducer during irradiation from the back. An increase in the efficiency of the photoelectric converter occurs due to a decrease in the distance from the generation region of nonequilibrium charge carriers in the region of separation. If the thickness of the base layer is less than 1 μm, then regardless of which side of the irradiation is carried out, a decrease in the efficiency of the instrument structure is observed. Increase in the efficiency of photoconverters is associated with an increase in the negative influence of recombination processes on the back contact, a decrease in the number of charge carriers generated due to incomplete absorption of incident radiation, and a decrease in the volume of the built-in field of the separating barrier when it overlaps with the depletion region of the back contact. ITO/CdS/CdTe/Cu/ITO SCs with a base layer thickness of 1 μm demonstrates degradation stability. The highest value of efficiency in the case of illumination from the front side 8.1 % and with illumination from the back side 3.8 % received after a year of operation of the photovoltaic converter.

Highlights

Today, advances in the production of high-performance photovoltaic converters are very successful
The creation of photoconverters based on thin films from a wide variety of materials and compounds is a promising direction in the development of solar energy
The concentration of nonequilibrium charge carriers generated by light in the back contact region increases, which leads to a decrease in the size of the depletion region and a corresponding decrease in shunt resistance

Summary

Introduction

Advances in the production of high-performance photovoltaic converters are very successful. The authors of [9] studied the conditions for the creation and operation of Cu/ITO transparent back contacts for film photoconverters with a CdTe base layer, which are intended for use in tandem and two-sided sensitive instrument structures. The aim of this research is the creation and study of solar cells with a thin base layer of CdTe suitable for use in tandem and two-sided sensitive structures To achieve this aim it is necessary to solve the following objectives: 1. 1. Results of the study of changes in the output parameters and diode characteristics of the ITO/CdS/CdTe/Cu/ITO PECs at different thicknesses of the base layer In this work, the CVCs of the instrument structures were measured upon irradiation on both sides with a change in the values of tbsh from 2.5 μm to 0.8 μm. ITO/CdS/CdTe/Cu/ITO output parameters and LDC of PEC upon irradiation from the front side

The thickness of the

Findings

Conclusions