Low-temperature Photoluminescence Studies of CdTe Thin Films Deposited on CdS/ZnO/Glass Substrates

2013 ◽  
Vol 1538 ◽  
pp. 261-267
Author(s):  
Corneliu Rotaru ◽  
Sergiu Vatavu ◽  
Christoph Merschjann ◽  
Chris Ferekides ◽  
Vladimir Fedorov ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Complex Structure ◽  
Excitation Power ◽  
Photoluminescence Spectra ◽  
Defect Band ◽  
Phonon Replica ◽  
Glass Substrates ◽  
Cdte Thin Films ◽  
Exciton Annihilation ◽  
Photoluminescence Studies

ABSTRACTThe CdTe photoluminescence spectra of CdTe/CdS/ZnO heterojunctions annealed in the presence of CdCl2 have been analyzed in the 4.7-100K temperature range. The analysis has been performed for laser excitation power between 0.01 mW and 30 mW. The analysis showed that the photoluminescence spectrum in the 1.1-1.6 eV region consists of a defect band (1.437 eV) having complex structure and revealing well contoured LO phonon replicas and bound exciton annihilation in the 1.587-1.593 eV region. The band analysis has been carried out by deconvoluting the spectra. It has been shown that the defect band consists of two elementary bands and their phonon replica. An “unusual” temperature dependence of the defect band has been found.

Excitation Power Dependence of Photoluminescence in CIB and FIB Implanted Superlattices

1991 ◽  
Vol 240 ◽  
Author(s):  
A. G. Choo ◽  
H. E. Jackson ◽  
P. Chen ◽  
A. J. Steckl ◽  
V. Gupta ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Peak Position ◽  
Excitation Power ◽  
Excitation Intensity ◽  
Power Dependence ◽  
Photoluminescence Spectra ◽  
Multiple Scan ◽  
Donor Acceptor ◽  
Low Temperature Photoluminescence

ABSTRACTLow temperature photoluminescence spectra have been used to characterize conventional ion beam (CIB) and focused ion beam (FIB) implanted superlattices. The excitation dependence of the single scan FIB is found to be significantly different from CIB and multiple scan FIB implantations which are similar. The peak position of the donor-acceptor transition is observed to change to higher energies significantly slower with excitation intensity for the single scan FIB case when compared to the multiple scan FIB and CIB cases. Simple models to describe these effects are briefly discussed.

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

MRS Advances ◽  
2018 ◽  
Vol 3 (52) ◽  
pp. 3135-3141 ◽  
Author(s):  
Niraj Shrestha ◽  
Dhurba R. Sapkota ◽  
Kamala K. Subedi ◽  
Puja Pradhan ◽  
Prakash Koirala ◽  
...  
Keyword(s):  
Thin Film ◽  
Laser Intensity ◽  
Copper Indium Diselenide ◽  
Defect States ◽  
Phonon Replica ◽  
Shallow Acceptor ◽  
Copper Indium ◽  
Defect Levels ◽  
Photoluminescence Studies ◽  
In Cis

Photoluminescence (PL) spectroscopy has been used to study the defect levels in thin film copper indium diselenide (CuInSe2, CIS) which we are developing as the absorber layer for the bottom cell of a monolithically grown perovskite/CuInSe2 tandem solar cell. Temperature and laser power dependent PL measurements of thin film CIS for two different Cu/In ratios (0.66 and 0.80) have been performed. The CIS film with Cu/In = 0.80 shows a prominent donor-to-acceptor peak (DAP) involving a shallow acceptor of binding energy ∼22 meV, with phonon replica at ∼32 meV spacing. In contrast, PL measurement of CIS film for Cu/In = 0.66 taken at 20 K exhibited an asymmetric and broad PL spectrum with peaks at 0.845 eV and 0.787 eV. Laser intensity dependent PL revealed that the observed peaks 0.845 eV and 0.787 eV shift towards higher energy (aka j-shift) at ∼11.7 meV/decade and ∼ 8 meV/decade with increase in laser intensity respectively. The asymmetric and broad spectrum together with large j-shift suggests that the observed peaks at 0.845 eV and 0.787 eV were related to band-to-tail (BT) and band-to-impurity (BI) transition, respectively. Such a band-tail-related transition originates from the potential fluctuation of defect states at low temperature. The appearance of band related transition in CIS film with Cu/In = 0.66 is the indicator of the presence of large number of charged defect states.

Zinc Oxide Nanostructures Fabricated under Extremely Non-Equilibrium Plasma Conditions

2019 ◽  
Vol 287 ◽  
pp. 75-79 ◽  
Author(s):  
Onkar Mangla ◽  
Savita Roy
Keyword(s):  
Zinc Oxide ◽  
Argon Plasma ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Plasma Dynamics ◽  
Glass Substrates ◽  
Tauc Plot ◽  
Mean Size ◽  
Photoluminescence Studies ◽  
Non Equilibrium

In the present work, extremely non-equilibrium, high temperature and high density argon plasma is used for producing ions from pellet of zinc oxide (ZnO) fitted on top of anode. These ions along with energetic argon ions move vertically upward in a fountain like structure in post focus phase of plasma dynamics and material ions get deposited on the glass substrates placed at 4.0 cm from anode top. This process of production of material ions from ZnO pellet leads to nucleation and nanostructures formation with one and two bursts of focused plasma. The surface morphology studied using scanning electron microscopy shows the formation of nanostructures with mean size about 8 nm. The structural properties of nanostructures in X-ray diffraction pattern show [100] and [002] planes of hexagonal ZnO. Photoluminescence studies show peaks related to defect transitions. The band-gap of nanostructures found from Tauc plot is smaller than that of the bulk ZnO. The resultant morphological, structural and optical properties of nanostructures suggest the possible applications in visible optoelectronic devices.

Photoluminescence properties of Cu-doped CdTeSe alloyed quantum dots versus laser excitation power and temperature

2020 ◽  
Vol 218 ◽  
pp. 116838 ◽  
Author(s):  
N.T. Hien ◽  
P.M. Tan ◽  
H.T. Van ◽  
V.T.K. Lien ◽  
P.V. Do ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laser Excitation ◽  
Excitation Power ◽  
Photoluminescence Properties

Influence of Deposition Time and Source-Substrate Distance on Properties of CdTe Thin Films Using Close-Spaced Sublimation at Higher Source Temperature

2013 ◽  
Vol 716 ◽  
pp. 325-327
Author(s):  
Xiao Yan Dai ◽  
Cheng Wu Shi ◽  
Yan Ru Zhang ◽  
Min Yao
Keyword(s):  
Thin Films ◽  
Deposition Time ◽  
Near Infrared ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
X Ray ◽  
Source Temperature ◽  
Glass Substrates ◽  
Substrate Distance ◽  
Cdte Thin Films

In this paper, CdTe thin films were deposited on soda-lime glass substrates using CdTe powder as a source by close-spaced sublimation at higher source temperature of 700°C. The influence of the deposition time and the source-substrate distance on the chemical composition, crystal phase, surface morphology and optical band gap of CdTe thin films was systemically investigated by energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscope and the ultraviolet-visible-near infrared absorption spectra, respectively. At the deposition time of 60 min and the source-substrate distance of 5 mm, the CdTe thin films had pyramid appearance with the grain size of 15 μm.

Photoluminescence from Ion Implanted CdTe Crystals

2005 ◽  
Vol 865 ◽  
Author(s):  
Xiangxin Liu ◽  
A. D. Compaan
Keyword(s):  
Laser Excitation ◽  
Heavy Ion ◽  
Inert Atmosphere ◽  
Excitation Power ◽  
Acceptor Pair ◽  
Ion Accelerator ◽  
Donor Acceptor ◽  
Lattice Damage ◽  
Power Densities ◽  
Monte Carlo Simulation Program

AbstractWe have studied the photoluminescence of CdTe crystals doped with two elements, Cu and Cl, that are frequently used in CdTe-based solar cells. Ions were implanted into high-quality single crystals of CdTe at the Toledo Heavy Ion Accelerator Lab in our Department. We used a standard Monte Carlo simulation program to plan an implant dosage at three different energies. The lattice damage was removed by thermal annealing in an inert atmosphere using a proximity cap to avoid surface deterioration. The PL spectra at 40K were obtained at 488 nm or 752nm to match the absorption depth with the implant profile. Using implant densities typically of 1016, 1017, and 1018 /cm3, and laser excitation power densities ranging over several orders of magnitude, we have identified band-to-band transitions, free-to-bound transitions, bound-exciton lines, and donor-acceptor pair transitions related to these species.

Thin Film Depositions of CdTe Semiconductors on Amorphous and Single Crystal Substrates and Comparisons of their Properties

2010 ◽  
Vol 638-642 ◽  
pp. 2909-2914 ◽  
Author(s):  
Yuichi Sato ◽  
Tatsushi Kodate ◽  
Manabu Arai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Substrate Temperature ◽  
Single Crystal ◽  
Photoluminescence Properties ◽  
Glass Substrates ◽  
Indium Doping ◽  
Sapphire Single Crystal ◽  
Cdte Thin Films ◽  
The Difference

Thin films of CdTe semiconductors were prepared on sapphire single crystal and quartz glass substrates by a vacuum evaporation method. Crystallinity and photoluminescence properties of the obtained CdTe thin films on the substrates were semi-quantitatively compared concerning the difference of the substrate materials. Dependences of the properties on the substrate temperature in the preparations and indium doping to the thin films were also investigated.

Effect of Growth Conditions on Defect-related Photoluminescence in ZnO Thin Films Grown by Plasma Assisted MBE

2007 ◽  
Vol 1035 ◽  
Author(s):  
Vitaliy Avrutin ◽  
Mikhail A. Reshchikov ◽  
Natalia Izyumskaya ◽  
Ryoko Shimada ◽  
Hadis Morkoç
Keyword(s):  
Oxygen Plasma ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Zno Thin Films ◽  
Zno Films ◽  
Near Band Edge ◽  
Photoluminescence Spectra ◽  
Rf Power ◽  
Defect Band ◽  
Excitonic Emission

AbstractThe effect of growth conditions on the luminescence properties of ZnO films grown on a-Al2O3/GaN(0001)/c-Al2O3 templates by plasma-assisted molecular beam epitaxy has been investigated. We observed that the deflecting of the ions produced by the RF oxygen plasma away from substrate results in improved excitonic emission and modification of the defect-related PL spectrum. The intensity of the near-band-edge lines in photoluminescence spectra from the layers grown with the ion deflector deflection was found to increase as compared to the controls grown without the ion deflector. The yellow-green spectral range was dominated by different defect bands in the films grown with and without ion deflection. The effect of RF power on peak positions of the defect band was studied for the films grown without ion deflection.

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