Characterisation of CdS vertical bar CdTe heterojunctions by photocurrent spectroscopy and electrolyte electroreflectance/absorbance spectroscopy (EEA/EER)

N W Duffy, L M Peter, R L Wang

Research output: Contribution to journalArticle

Abstract

Thin films (0.02-2.0 mum) of CdTe were electrodeposited from an acidic electrolyte containing a high concentration of Cd2+ and a low concentration of TeO2 using chemically prepared US layers on fluorine-doped tin oxide coated glass as substrates. Characterisation of the as-deposited and thermally annealed CdTe\CdS heterostructures by photocurrent spectroscopy was carried out using transparent stabilising electrolyte contacts (1.0 M Na2SO3), which allowed illumination from the CdTe or CdS (glass) sides. The same electrolyte was used for electrolyte electroabsorption and electroreflectance spectroscopy (EEA/EER). Comparison of the photocurrent spectra for the two illumination directions allowed detection of type conversion and junction formation arising from heat treatment. The as-deposited CdTe films were n-type, and heat treatment at 415 degreesC resulted in conversion to p-type with formation of a heterojunction with the CdS. In the thinnest structures studied, photocurrent spectroscopy showed that the US film remained photoactive after heat treatment, and a clear US response could also be seen in the electroabsorbance spectra. Heat treatment of CdS\CdTe structures with thicker CdTe films (> 0.2 mum) resulted in a formation of a photo-inactive US layer, which gave rise to the well-known loss of photoresponse in the blue that is characteristic of CdS\CdTe solar cells. Electrolyte electroabsorbance and electroreflectance measurements showed that annealing changed the hand gap of the CdTe, and this is attributed to CdTe1-xSx alloy formation (x = 0.05-0.07). (C) 2002 Elsevier Science B.V. All rights reserved.
LanguageEnglish
Pages207-214
Number of pages8
JournalJournal of Electroanalytical Chemistry
Volume532
Issue number1-2
StatusPublished - 2002

Fingerprint

Photocurrents
Electrolytes
Heterojunctions
Spectroscopy
Heat treatment
Lighting
Glass
Fluorine
Tin oxides
Thick films
Solar cells
Annealing
Thin films
Substrates

Cite this

@article{704c648b132a42b88cf4874dce260a80,
title = "Characterisation of CdS vertical bar CdTe heterojunctions by photocurrent spectroscopy and electrolyte electroreflectance/absorbance spectroscopy (EEA/EER)",
abstract = "Thin films (0.02-2.0 mum) of CdTe were electrodeposited from an acidic electrolyte containing a high concentration of Cd2+ and a low concentration of TeO2 using chemically prepared US layers on fluorine-doped tin oxide coated glass as substrates. Characterisation of the as-deposited and thermally annealed CdTe\CdS heterostructures by photocurrent spectroscopy was carried out using transparent stabilising electrolyte contacts (1.0 M Na2SO3), which allowed illumination from the CdTe or CdS (glass) sides. The same electrolyte was used for electrolyte electroabsorption and electroreflectance spectroscopy (EEA/EER). Comparison of the photocurrent spectra for the two illumination directions allowed detection of type conversion and junction formation arising from heat treatment. The as-deposited CdTe films were n-type, and heat treatment at 415 degreesC resulted in conversion to p-type with formation of a heterojunction with the CdS. In the thinnest structures studied, photocurrent spectroscopy showed that the US film remained photoactive after heat treatment, and a clear US response could also be seen in the electroabsorbance spectra. Heat treatment of CdS\CdTe structures with thicker CdTe films (> 0.2 mum) resulted in a formation of a photo-inactive US layer, which gave rise to the well-known loss of photoresponse in the blue that is characteristic of CdS\CdTe solar cells. Electrolyte electroabsorbance and electroreflectance measurements showed that annealing changed the hand gap of the CdTe, and this is attributed to CdTe1-xSx alloy formation (x = 0.05-0.07). (C) 2002 Elsevier Science B.V. All rights reserved.",
author = "Duffy, {N W} and Peter, {L M} and Wang, {R L}",
note = "ID number: ISI:000178501000025",
year = "2002",
language = "English",
volume = "532",
pages = "207--214",
journal = "Journal of Electroanalytical Chemistry",
issn = "1572-6657",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Characterisation of CdS vertical bar CdTe heterojunctions by photocurrent spectroscopy and electrolyte electroreflectance/absorbance spectroscopy (EEA/EER)

AU - Duffy,N W

AU - Peter,L M

AU - Wang,R L

N1 - ID number: ISI:000178501000025

PY - 2002

Y1 - 2002

N2 - Thin films (0.02-2.0 mum) of CdTe were electrodeposited from an acidic electrolyte containing a high concentration of Cd2+ and a low concentration of TeO2 using chemically prepared US layers on fluorine-doped tin oxide coated glass as substrates. Characterisation of the as-deposited and thermally annealed CdTe\CdS heterostructures by photocurrent spectroscopy was carried out using transparent stabilising electrolyte contacts (1.0 M Na2SO3), which allowed illumination from the CdTe or CdS (glass) sides. The same electrolyte was used for electrolyte electroabsorption and electroreflectance spectroscopy (EEA/EER). Comparison of the photocurrent spectra for the two illumination directions allowed detection of type conversion and junction formation arising from heat treatment. The as-deposited CdTe films were n-type, and heat treatment at 415 degreesC resulted in conversion to p-type with formation of a heterojunction with the CdS. In the thinnest structures studied, photocurrent spectroscopy showed that the US film remained photoactive after heat treatment, and a clear US response could also be seen in the electroabsorbance spectra. Heat treatment of CdS\CdTe structures with thicker CdTe films (> 0.2 mum) resulted in a formation of a photo-inactive US layer, which gave rise to the well-known loss of photoresponse in the blue that is characteristic of CdS\CdTe solar cells. Electrolyte electroabsorbance and electroreflectance measurements showed that annealing changed the hand gap of the CdTe, and this is attributed to CdTe1-xSx alloy formation (x = 0.05-0.07). (C) 2002 Elsevier Science B.V. All rights reserved.

AB - Thin films (0.02-2.0 mum) of CdTe were electrodeposited from an acidic electrolyte containing a high concentration of Cd2+ and a low concentration of TeO2 using chemically prepared US layers on fluorine-doped tin oxide coated glass as substrates. Characterisation of the as-deposited and thermally annealed CdTe\CdS heterostructures by photocurrent spectroscopy was carried out using transparent stabilising electrolyte contacts (1.0 M Na2SO3), which allowed illumination from the CdTe or CdS (glass) sides. The same electrolyte was used for electrolyte electroabsorption and electroreflectance spectroscopy (EEA/EER). Comparison of the photocurrent spectra for the two illumination directions allowed detection of type conversion and junction formation arising from heat treatment. The as-deposited CdTe films were n-type, and heat treatment at 415 degreesC resulted in conversion to p-type with formation of a heterojunction with the CdS. In the thinnest structures studied, photocurrent spectroscopy showed that the US film remained photoactive after heat treatment, and a clear US response could also be seen in the electroabsorbance spectra. Heat treatment of CdS\CdTe structures with thicker CdTe films (> 0.2 mum) resulted in a formation of a photo-inactive US layer, which gave rise to the well-known loss of photoresponse in the blue that is characteristic of CdS\CdTe solar cells. Electrolyte electroabsorbance and electroreflectance measurements showed that annealing changed the hand gap of the CdTe, and this is attributed to CdTe1-xSx alloy formation (x = 0.05-0.07). (C) 2002 Elsevier Science B.V. All rights reserved.

M3 - Article

VL - 532

SP - 207

EP - 214

JO - Journal of Electroanalytical Chemistry

T2 - Journal of Electroanalytical Chemistry

JF - Journal of Electroanalytical Chemistry

SN - 1572-6657

IS - 1-2

ER -