The Influence of Surface Recombination and Trapping on the Cathodic Photocurrent at p‐Type III‐V Electrodes

1982 ◽  
Vol 129 (4) ◽  
pp. 730-738 ◽  
Author(s):  
J. J. Kelly ◽  
R. Memming
1970 ◽  
Vol 17 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Karolis GULBINAS ◽  
Vytautas GRIVICKAS ◽  
Haniyeh P. MAHABADI ◽  
Muhammad USMAN ◽  
Anders HALLÉN

n- and p-type 4H-SiC epilayers were grown on heavily doped SiC substrates. The thickness of the p-type layer was 7 µm and the doping level around 1017 cm 3, while the n-type epilayers were 15 µm thick and had a doping concentration of 3 - 5*1015 cm 3. Several different surface treatments were then applied on the epilayers for surface passivation: SiO2 growth, Al2O3 deposited by atomic layer deposition, and Ar-ion implantation. Using collinear pump - probe technique the effective carrier lifetimes were measured from various places and statistical lifetime distributions were obtained. For surface recombination evaluation, two models are presented. One states that surface recombination velocity (SRV) is equal on both the passivation/epi layer interface (S2) and the deeper interface between the epilayer and the SiC substrate i. e. (S1 = S2). The other model is simulated assuming that SRV in the epilayer/substrate (S1) interface is constant while in the passivation layer/epilayer (S2) interface SRV can be varied S2 < S1. Empirical nomograms are presented with various parameters sets to evaluate S2 values. We found that on the investigated 4H-SiC surfaces S2 ranges from 3x104 to 5x104 assuming that the bulk lifetime is 4 (µs. In Ar+ implanted surfaces S2 is between (105 - 106) cm/s.http://dx.doi.org/10.5755/j01.ms.17.2.479


1992 ◽  
Vol 39 (1) ◽  
pp. 184-192 ◽  
Author(s):  
A. Katz ◽  
S.N.G. Chu ◽  
B.E. Weir ◽  
C.R. Abernathy ◽  
W.S. Hobson ◽  
...  

1994 ◽  
Vol 08 (10) ◽  
pp. 1247-1342 ◽  
Author(s):  
S.J. PEARTON

The properties of hydrogen in III–V semiconductors are reviewed. Atomic hydrogen is found to passivate the electrical activity of shallow donor and acceptor dopants in virtually all III–V materials, including GaAs, Alx Ga1−x As, InP, InGaAs, GaP, InAs, GaSb, InGaP, AlInAs and AlGaAsSb. The passivation is due to the formation of neutral dopant-hydrogen complexes, with hydrogen occupying a bond-centered position in p-type semiconductors and an anti-bonding site in n-type materials. The dopants are reactivated by annealing at ≤400° C. The neutral hydrogen-dopant complexes have characteristic vibrational bands, around 2000cm−1 for stretching modes and 800cm−1 for wagging modes. Deep levels such as EL2, DX and metallic impurities are also passivated by hydrogen. The diffusivity of hydrogen is high in III–V semiconductors and unintentional incorporation can occur during epitaxial growth, annealing in H2, dry etching, water boiling, wet etching or chemical vapor deposition processes, Surface passivation by (NH4)xS or NH3 plasma treatment is also effective in lowering surface recombination velocities in many III-V semiconductors.


2010 ◽  
Vol 31 (4) ◽  
pp. 305-307 ◽  
Author(s):  
J. Knoch ◽  
J. Appenzeller
Keyword(s):  
Type Iii ◽  

1989 ◽  
Vol 50 (C6) ◽  
pp. C6-187-C6-187
Author(s):  
I. DELIDAIS ◽  
P. MAUGIS ◽  
D. BALLUTAUD ◽  
N. TABET ◽  
J.-L. MAURICE

2009 ◽  
Vol 615-617 ◽  
pp. 821-824 ◽  
Author(s):  
Kenichi Nonaka ◽  
Akihiko Horiuchi ◽  
Yuki Negoro ◽  
Kensuke Iwanaga ◽  
Seiichi Yokoyama ◽  
...  

A new 4H-SiC Bipolar Junction Transistor with Suppressed Surface Recombination structure: SSR-BJT has been proposed to improve the common emitter current gain which is one of the main issues for 4H-SiC BJTs. A Lightly Doped N-type layer (LDN-layer) between the emitter and base layers, and a High Resistive P-type region (HRP-region) formed between the emitter mesa edge and the base contact region were employed in the SSR-BJT. A fabricated SSR-BJT showed a maximum current gain of 134 at room temperature with a specific on-resistance of 3.2 mΩcm2 and a blocking voltage VCEO of 950 V. The SSR-BJT kept a current gain of 60 at 250°C with a specific on-resistance of 8 mΩcm2. To our knowledge, these current gains are the highest among 4H-SiC BJTs with a blocking voltage VCEO more than about 1000 V which have been ever reported.


1985 ◽  
Vol 63 (6) ◽  
pp. 870-875 ◽  
Author(s):  
S. Damaskinos ◽  
A. E. Dixon

A scanning laser microscope was used to study the electronic and recombination properties at grain boundaries of both n- and p-type Wacker polycrystalline silicon in a spatially resolved photoconductivity experiment. The light energy falling on the samples was varied over five orders of magnitude from 10−1 to 10−6 mW. For p-type material the measured L decreased with beam intensity from 150 to 60 μm, reaching a constant value at very low beam intensities. The small focal spot of the microscope allowed the measurements to be extended to include n-type samples. Forthese samples L was found to change from 90 to 18 μm with decreasing beam intensity. The surface recombination velocity SGB was evaluated for both samples. For p-type samples it decreased from 25 000 to 6000 cm/s and for n-type samples from 21 000 to 3000 cm/s with decreasing beam intensity. The quasi-Fermi level separation was determined as a function of the excess minority-carrier-concentration density at the grain boundary and found to increase linearly with beam intensity.


2018 ◽  
Vol 43 ◽  
pp. 01006 ◽  
Author(s):  
Ferdiansjah ◽  
Faridah ◽  
Kelvian Tirtakusuma Mularso

Back Surface Field (BSF) has been used as one of means to enhance solar cell performance by reducing surface recombination velocity (SRV). One of methods to produce BSF is by introducing highly doped layer on rear surface of the wafer. Depending on the type of the dopant in wafer, the BSF layer could be either p+ or n+. This research aims to compare the performance of BSF layer both in p-type and n-type wafer in order to understand the effect of BSF on both wafer types. Monociystalline silicon wafer with thickness of 300 μm. area of 1 cm2, bulk doping level NB = 1.5×1016/cm3 both for p-type wafer and n-type wafer are used. Both wafer then converted into solar cell by adding emitter layer with concentration NE =7.5×1018/cm3 both for p-type wafer and n-type wafer. Doping profile that is used for emitter layer is following complementary error function (erfc) distribution profile. BSF concentration is varied from 1×1017/cm3 to 1×1020/cm3 for each of the cell. Solar cell performance is tested under standard condition, with AM1.5G spectrum at 1000 W/m2. Its output is measured based on its open circuit voltage (Voc). short circuit current density (JSC), efficiency (η). and fill factor (FF). The result shows that the value of VOC is relatively constant along the range of BSF concentration, which is 0.694 V – 0.702 V. The same pattern is also observed in FF value which is between 0.828 – 0.831. On the other hand, value of JSC and efficiency will drop against the increase of BSF concentration. Highest JSC which is 0.033 A/cm2 and highest efficiency which is 18.6% is achieved when BSF concentration is slightly higher than bulk doping level. The best efficiency can be produced when BSF concentration is around 1×1017cm-3.. This result confirms that surface recombination velocity has been reduced due to the increase in cell’s short circuit current density and its efficiency. In general both p-type and n-type wafer will produce higher efficiency when BSF is applied. However, the increase is larger in p-type wafer than in n-type wafer. Better performance for solar cell is achieved when BSF concentration is slightly higher that bulk doping level because at very high BSF concentration the cell’s efficiency will be decreased.


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