Development of system for automatic measurement of transient photocurrent and thermally stimulated current

Asdrubal Antonio Ramirez Botero,Gerardo Gordillo

doi:10.15446/ing.investig.v37n1.60765

Asdrubal Antonio Ramirez Botero, Gerardo Gordillo

Open Access

https://doi.org/10.15446/ing.investig.v37n1.60765

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Abstract

This paper presents details of the design and implementation of a system for measuring of thermally stimulated current (TSC) and transient photocurrent (Iph), developed using the Virtual Instrumentation concept. For that we have used National Instrument hardware and the LabView® package as software. The system is controlled by a virtual instrument (VI) which includes facilities to perform measurements of photocurrent keeping the temperature of the sample and the pressure of the chamber of measurement controlled as well as real time display of the Iph vs t and TSC vs T curves. The system was tested by performing transient photocurrent and TSC measurements on CH3NH3PbI3 thin films that are generally used as absorbent layer of solar cells. This type of characterization is very useful to get information of the trapping and recombination processes that affect the transport properties of the devices.

Highlights

The control of processes, the acquisition and monitoring of data with automatic systems that include analogical and digital variables, generally follow a traditional architecture that employs data loggers or microcontrollers [R. Mukaro et al, 1998; 1999]
The system developed allows measurement of transient photocurrent maintaining controlled both the temperature of the sample as the pressure of the chamber of measurement; this system includes facilities to vary the temperature at a constant rate in the range of 2-30 °C/min
The functions of control, measurement, acquisition, processing and display of data are made through a Virtual instrument (VI) developed with LabVIEW

Summary

Introduction

The control of processes, the acquisition and monitoring of data with automatic systems that include analogical and digital variables, generally follow a traditional architecture that employs data loggers or microcontrollers [R. Mukaro et al, 1998; 1999]. The aim of this work is to introduce a system that was designed and implemented for measuring of thermally stimulated current (TSC) and transient photocurrent using Virtual Instrumentation [R. The system developed was proven performing measures of TSC and transient photocurrent to thin films of the organic/inorganic hybrid compound CH3NH3PbI3 with structure perovskite, used in the manufacture of solar cells by our research group. The equipment allows realizing photocurrent measurements at different pressures, which are controlled through an electronic mass flow controller connected to a cylinder with compressed air, keeping the vacuum system in operation This system allows generating ramps of temperature at a constant rate in the range of 2-30 °C/min, which is necessary to be able to do TSC measurements. The functions of control, measurement, acquisition, processing and display of data are made through a Virtual instrument (VI) developed with LabVIEW

System of heating and cooling of the sample

Conclusions