A DLTS study of a ZnO microwire, a thin film and bulk material

2014 ◽  
Vol 1633 ◽  
pp. 51-54
Author(s):  
Florian Schmidt ◽  
Peter Schlupp ◽  
Stefan Müller ◽  
Christof Peter Dietrich ◽  
Holger von Wenckstern ◽  
...  
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Deep Level ◽  
Bulk Material ◽  
Intrinsic Defect ◽  
Growth Technique ◽  
Current Voltage ◽  
Common Opinion ◽  
Transient Spectroscopy ◽  
Zno Single Crystal

ABSTRACTWe have investigated the electrical properties of a ZnO microwire grown by carbo-thermal evaporation, a ZnO thin film grown by pulsed-laser deposition on an a-plane sapphire, and a hydrothermally grown Zn-face ZnO single crystal (Tokyo Denpa Co. Ltd.). The samples were investigated by means of current-voltage measurements, capacitance-voltage measurements, and deep-level transient spectroscopy.The defects T2 [1,2] and E3 [1,3,4] were identified in all three sample types. Additionally, in the single crystal and thin film samples E64 [5] and E4 [1] were detected. These findings support the common opinion that T2 is an intrinsic defect since it is found in all the samples investigated and thus its occurrence is not related to any growth technique.

Preparation and electrical properties of heterojunctions of ZnO on Zn3P2 and CdTe

1989 ◽  
Vol 67 (4) ◽  
pp. 448-455 ◽  
Author(s):  
M. Ginting ◽  
J. D. Leslie
Keyword(s):  
Single Crystal ◽  
Deep Level ◽  
Photovoltaic Performance ◽  
Polycrystalline Film ◽  
Metal Insulator ◽  
Measurement And Analysis ◽  
Transient Spectroscopy ◽  
P Type ◽  
Zno Single Crystal ◽  
High Series

"Heterojunctions" have been fabricated by the reactive evaporation of thin film n-type ZnO onto p-type single crystal Zn3P2, polycrystalline films of Zn3P2, and single crystal CdTe. The photovoltaic response of the n-ZnO – single crystal p-CdTe devices was good, that of the n-ZnO – single crystal p-Zn3P2 devices was poor, and that of the n-ZnO – p-Zn3P2 polycrystalline film devices was nonexistent. The ideality factor n of all devices studied was greater than two. On the basis of 1/C2 vs. V results, the n-ZnO – single crystal p-Zn3P2 devices behaved most like Schottky barrier devices, whereas the n-ZnO – p-Zn3P2 polycrystalline film devices, and the n-ZnO – p-single crystal CdTe "heterojunctions" behaved most like metal–insulator–semiconductor devices. The high series resistance of all devices had to be considered in the measurement and analysis, and it limited the photovoltaic performance. Deep-level transient spectroscopy measurements indicated majority (hole) traps in the CdTe and Zn3P2 with activation energies in agreement with previous measurements in the literature.

scholarly journals Correlation between Defects and Electrical Performances of Ion-Irradiated 4H-SiC p–n Junctions

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1966
Author(s):  
Domenico Pellegrino ◽  
Lucia Calcagno ◽  
Massimo Zimbone ◽  
Salvatore Di Franco ◽  
Antonella Sciuto
Keyword(s):  
Deep Level ◽  
Electrical Characterization ◽  
High Fluence ◽  
Defect States ◽  
Exponential Parameter ◽  
Current Voltage ◽  
Different Temperatures ◽  
In Series ◽  
Transient Spectroscopy ◽  
Fluence Range

In this study, 4H-SiC p–n junctions were irradiated with 700 keV He+ ions in the fluence range 1.0 × 1012 to 1.0 × 1015 ions/cm2. The effects of irradiation were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements, while deep-level transient spectroscopy (DLTS) was used to study the traps introduced by irradiation defects. Modifications of the device’s electrical performances were observed after irradiation, and two fluence regimes were identified. In the low fluence range (≤1013 ions/cm2), I–V characteristics evidenced an increase in series resistance, which can be associated with the decrease in the dopant concentration, as also denoted by C–V measurements. In addition, the pre-exponential parameter of junction generation current increased with fluence due to the increase in point defect concentration. The main produced defect states were the Z1/2, RD1/2, and EH6/7 centers, whose concentrations increased with fluence. At high fluence (>1013 ions/cm2), I–V curves showed a strong decrease in the generation current, while DLTS evidenced a rearrangement of defects. The detailed electrical characterization of the p–n junction performed at different temperatures highlights the existence of conduction paths with peculiar electrical properties introduced by high fluence irradiation. The results suggest the formation of localized highly resistive regions (realized by agglomeration of point defects) in parallel with the main junction.

A Novel Technique for Growth of Lithium-free ZnO Single Crystals

2013 ◽  
Vol 1538 ◽  
pp. 405-410
Author(s):  
Shaoping Wang ◽  
Aneta Kopec ◽  
Andrew G. Timmerman
Keyword(s):  
Single Crystal ◽  
The Novel ◽  
Uv Laser ◽  
Uv Detectors ◽  
Growth Technique ◽  
Light Emitting ◽  
Alkaline Metals ◽  
Novel Technique ◽  
Solar Blind ◽  
Zno Single Crystal

ABSTRACTA ZnO single crystal is a native substrate for epitaxial growth of high-quality thin films of ZnO-based Group II-oxides (e.g. ZnO, ZnMgO, ZnCdO) for variety of devices, such as UV and visible-light emitting diodes (LEDs), UV laser diodes and solar-blind UV detectors. Currently, commercially available ZnO single crystal wafers are produced using a hydrothermal technique. The main drawback of hydrothermal growth technique is that the ZnO crystals contain large amounts of alkaline metals, such as Li and K. These alkaline metals are electrically active and hence can be detrimental to device performances. In this paper, results from a recently developed novel growth technique for ZnO single crystal boules are presented. Lithium-free ZnO single crystal boules of up to 1 inch in diameter was demonstrated using the novel technique. Results from crystal growth and materials characterization will be discussed.

Transport Properties and Conduction Band Offset of n-ZnO/n-6H-SiC Heterostructures

2006 ◽  
Vol 957 ◽  
Author(s):  
Yahya Alivov ◽  
Xiao Bo ◽  
Fan Qian ◽  
Daniel Johnstone ◽  
Cole Litton ◽  
...  
Keyword(s):  
Conduction Band ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Band Offset ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Conduction Band Offset ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Transient Spectroscopy

ABSTRACTThe conduction band offset of n-ZnO/n-6H-SiC heterostructures fabricated by rf-sputtered ZnO on commercial n-type 6H-SiC substrates has been measured. Temperature dependent current-voltage characteristics, photocapacitance, and deep level transient spectroscopy measurements showed the conduction band offsets to be 1.25 eV, 1.1 eV, and 1.22 eV, respectively.

Electronic Properties of ZnO/Si Heterojunction Prepared by ALD.

2011 ◽  
Vol 178-179 ◽  
pp. 130-135 ◽  
Author(s):  
Vincent Quemener ◽  
Mari Alnes ◽  
Lasse Vines ◽  
Ola Nilsen ◽  
Helmer Fjellvåg ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Deep Level ◽  
Atomic Layer ◽  
Substantial Improvement ◽  
Conduction Band Edge ◽  
Energy Position ◽  
Layer Deposition ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Transient Spectroscopy

ZnO/n-Si and ZnO/p-Si heterostructures were prepared by Atomic layer deposition (ALD) and the electronic properties have been investigated by Current-Voltage (I-V), Capacitance-Voltage (C-V) and Deep level transient spectroscopy (DLTS) measurements. DLTS measurements show two dominants electron traps at the interface of the ZnO/n-Si junction with energy position at 0.07 eV and 0.15 eV below the conduction band edge, labelled E(0.07) and E(0.15), respectively, and no electrically active defects at the interface of the ZnO/p-Si junction. E(0.07) is reduced by annealing up to 400°C while E(0.15) is created at 500°C. The best heterostructure is found after heat treatment at 400°C with a substantial improvement of the current rectification for ZnO/n-Si and the formation of Ohmic contact on ZnO/p-Si. A reduction of the interface defects correlates with an improvement of the crystal structure of the ZnO film with a preferred orientation along the c-axis.

Electrical Characterization of N+-implanted n-type ZnO Single Crystals: p-n Homojunction and Deep Level Defects

2007 ◽  
Vol 1035 ◽  
Author(s):  
Qilin Gu ◽  
Xuemin Dai ◽  
Chi-Chung Ling ◽  
Shijie Xu ◽  
Liwu Lu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Thermal Evolution ◽  
Deep Level ◽  
Schottky Diodes ◽  
Control Sample ◽  
Electrical Characterization ◽  
Type Layer ◽  
Current Voltage ◽  
Transient Spectroscopy ◽  
Induced Defects

AbstractUnintentionally doped n-type ZnO single crystals were implanted by nitrogen ions with different fluences of 1013, 1014 and 1015 cm−2 respectively. ZnO p-n homojunction was successfully fabricated due to the formation of p-type layer after 650°C post-implantation annealing in air for 30 minutes. Further thermal evolution of deep level defects was studied through thermal annealing up to 1200°C. Electrical characterization techniques including current-voltage (I-V), capacitance-voltage (C-V), Deep Level Transient Spectroscopy (DLTS) and double-correlation DLTS (DDLTS) were used for investigating the control sample, all the as-implanted and annealed samples through Au/n-ZnO Schottky diodes as well as ZnO p-n junctions. Detailed electrical properties of fabricated devices and characteristics of implantation induced defects were analyzed based on plentiful DLTS spectra. Moreover, low-temperature photoluminescence experiments of all the as-implanted and annealed samples were performed and the correlation between results from electrical and optical characterizations was discussed.

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