Degradation of Hydrogen-Passivated p-Type Layers in GaAs by Minority Carrier Injection and Reverse Bias Annealing

1990 ◽  
Vol 184 ◽  
Author(s):  
A. J. Tavendale ◽  
S. J. Pearton ◽  
A. A. Williams ◽  
D. Alexiev

ABSTRACTWe detail experiments showing that acceptor passivation by atomic hydrogen in p-type GaAs is unstable to either illumination, forward bias annealing or reverse bias annealing. The long-term stability of operation of devices employing hydrogen in or near the active region of FETs or quantum-well lasers is therefore questionable. The systematics of acceptor reactivation during minority carrier injection or reverse bias annealing are presented.

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1116 ◽  
Author(s):  
Eusebiu Ionete ◽  
Stefan Spiridon ◽  
Bogdan Monea ◽  
Elena Stratulat

The electrical response of sulfonated single-walled carbon nanotubes (SWCNTs) to NO and NO2, for gas sensing applications, at room temperature, is reported in this work. A specific configuration based on SWCNT deposition between double pair configuration gold electrodes, supported on a substrate, was considered for the sensing device; employed characterization technique where FTIR and SEM. The experimental results showed a p-type response of the sulfonated SWCNTs, with decrease in resistance, under exposure to NO gas (40–200 ppb) and NO2 (40–200 ppb). Also, the sensor responses to successive exposures at NO2 800 ppb together with investigation of long term stability, at 485 ppb for NO, are reported. The reaction mechanism in case of NO and NO2 detection with sulfonated SWCNTs is presented.


1986 ◽  
Vol 70 ◽  
Author(s):  
R. E. Rocheleau ◽  
S. C. Jackson. ◽  
S. S. Hegedus ◽  
B. N. Baron

ABSTRACTChemical vapor deposition techniques, in particular plasma enhanced CVD, have been used to produce high quality a-Si:H materials. Continuing research is directed toward increased device performance, improved stability, and translation of scale to commercial production. A part of this effort is the evaluation of alternate CVD techniques which in addition to providing technical options for high efficiency and long term stability are likely to lead to improved understanding of the relationships between deposition processes and material properties. A relatively new technique for depositing a-Si:H is photo-CVD which utilizes ultraviolet light to initiate the decomposition of silane or disilane. The best results from both materials properties and device efficiency points of view have been achieved using mercury sensitized photo-CVD. Recently, a 10.5% efficient a-Si:H p-i-n photovoltaic cell, fabricated by photo-CVD, was reported [1]. A limitation in photo-CVD has been preventing deposition on the UV transparent window. In this paper we describe a new photo-CVD reactor with a moveable UV-transparent Teflon film and secondary gas flows to eliminate window fouling. The deposition and opto-electronic characterization of intrinsic a-Si:H and a-SiGe:H and p-type a-SiC:H are described. Finally, preliminary results of p-i-n solar cells are presented.


2017 ◽  
Vol 1 (3) ◽  
pp. 626-635 ◽  
Author(s):  
Nathalie Marinakis ◽  
Markus Willgert ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

The balance between optimal photoconversion efficiency and long-term stability in p-type DSCs with a cyclometallated ruthenium dye is presented, with mixtures of acetonitrile and propionitrile being the best solvent with an I3−/I− redox couple.


2010 ◽  
Vol 49 (9) ◽  
pp. 091302 ◽  
Author(s):  
Orhan Özdemir ◽  
U. Deneb Yilmazer ◽  
Beyhan Tatar ◽  
Mustafa Ürgen ◽  
Kubilay Kutlu

1992 ◽  
Vol 258 ◽  
Author(s):  
K.J.B.M. Nieuwesteeg ◽  
J. Boogaard ◽  
G. Oversluizen

ABSTRACTForward-bias current stress experiments were performed on α-Si:H p-i-n and Schottky switches at several temperatures and at current densities up to 6 A/cm2. In Schottky diodes, current stressing results in a lowering of the forward-bias SCLC current together with an increase of its thermal activation energy. The reverse current is unaffected. The rate of degradation of the forward current increases with increasing temperature. From a comparison of the degradation behaviour of Schottky's with different barrier height we find that the rate of degradation is correlated to the minority-carrier injection ratio of the Schottky contact. The effects are interpreted as being due to metastable state creation in the bulk α-Si:H. The rectifying properties of the metal-to-semiconductor contact are relatively stable to current stress.The forward-bias I-V curves of p-i-n diodes degrade much faster than those of the Schottky switches. At the same time, the reverse-bias current increases due to the stress. The lower stability to current-stress of p-i-n diodes is ascribed to the much higher hole injection in the mesa. After a short time, the reverse-bias current becomes dominated by e-h generation from the created deep states in the i-layer and then gives a direct indication of its time dependence.


1992 ◽  
Vol 283 ◽  
Author(s):  
H. Paul Maruska ◽  
F. Namavar ◽  
N. M. Kalkhoran

ABSTRACTWe discuss the operation of porous silicon light-emitting diodes prepared as heterojunctions between n-type In2O3:Sn (ITO) and p-type silicon nanostructures, exhibiting quantum confinement effects. The transparent ITO affords light emission through the top surface of the device, as well as providing passivation and hence long term stability. We describe a model for the injection of minority carrier electrons into the porous silicon regions, which results in the emission of yellow-orange DC electroluminescence. A detailed study of the forward bias current-voltage characteristics of the devices will be given, which allows calculations of the densities of interface states. A tendency to pin the hole fermi energy near the neutral level, φ0, is shown to control the extraction of majority carriers. Methods for improving LED efficiency by alleviating a parasitic shunt current path through interface states will be addressed.


2001 ◽  
Vol 668 ◽  
Author(s):  
Jutta Beier ◽  
Marc Köntges ◽  
Peter Nollet ◽  
Stefaan Degrave ◽  
Marc Burgelman

ABSTRACTIn previous work [1,2], we modeled the cross-over of the I-V curves of thin film CdS/CdTe solar cells in terms of an electron (minority carrier) current in the vicinity of the back contact. In this work, we focus on the necessary extension of this analytical model based on a series of measurement results. Especially the wavelength and voltage dependence of the current at forward bias is illustrated in these measurements. The various possible causes for this kind of behavior are discussed and modeled. The extensions to the previous model, needed to describe the voltage and wavelength dependent behavior of I-V curves of real CdTe/CdS solar cells, are proposed.


1997 ◽  
Vol 46 (1-3) ◽  
pp. 263-266 ◽  
Author(s):  
E.G. Stein von Kamienski ◽  
C. Leonhard ◽  
F. Portheine ◽  
A. Gölz ◽  
H. Kurz

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