Reducing Surface Recombination Velocity of Methylammonium-Free Mixed-Cation Mixed-Halide Perovskites via Surface Passivation

ABSTRACTThe effect of ammonium sulfide passivation on InAs/GaSb superlattice infrared detectors was investigated using two complementary techniques, namely, picosecond excitation correlation (PEC) measurement and variable-area diode array (VADA) surface recombination velocity (SRV) measurement. PEC measurements were conducted on etched InAs/GaSb superlattice mesas, which were passivated in aqueous ammonium sulfide solutions of various strengths for several durations. The PEC signal's decay time constant (DTC) is proportional to carrier lifetimes. At 77 K the PEC signal's DTC of the as-grown InAs/GaSb superlattice sample was 2.0 ns, while that of the unpassivated etched sample was reduced to 1.2 ns by the surface states at the mesa sidewalls. The most effective ammonium sulfide passivation process increased the PEC signal's DTC to 10.4 ns. However it is difficult to isolate surface recombination from other processes that contribute to the lifetime using the PEC data, therefore a VADA SRV measurement was undertaken to determine the effect of passivation on surface recombination. The obtained SRV in the depletion region of the InAs/GaSb superlattice and GaSb junction was 1.1×106 cm/s for the unpassivated sample and 4.6×105 cm/s for the passivated sample. At 77 K the highest R0A value measured in our passivated devices was 2540 W cm2 versus 0.22 W cm2 for the unpassivated diodes. The results of the lifetime, the SRV and the R0A measurements indicate that ammonium sulfide passivation will improve the performance of InAs/GaSb superlattice infrared detectors.

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Surface Recombination Investigation in Thin 4H-SiC Layers

Materials Science ◽

10.5755/j01.ms.17.2.479 ◽

1970 ◽

Vol 17 (2) ◽

pp. 119-124 ◽

Cited By ~ 4

Author(s):

Karolis GULBINAS ◽

Vytautas GRIVICKAS ◽

Haniyeh P. MAHABADI ◽

Muhammad USMAN ◽

Anders HALLÉN

Keyword(s):

Surface Passivation ◽

Surface Recombination ◽

Atomic Layer ◽

Surface Recombination Velocity ◽

Lifetime Distributions ◽

Carrier Lifetimes ◽

Layer Deposition ◽

Type Layer ◽

Recombination Velocity ◽

P Type

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

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Orientation Dependence Of Surface Passivation For Semi-Insulating Gaas

MRS Proceedings ◽

10.1557/proc-421-93 ◽

1996 ◽

Vol 421 ◽

Author(s):

I.P. Koutzarov ◽

C.H. Edirisinghe ◽

H.E. Ruda ◽

L.Z. Jedral ◽

Q. Liu ◽

...

Keyword(s):

Band Gap ◽

Surface Passivation ◽

Dielectric Film ◽

Surface Recombination ◽

Orientation Dependence ◽

Film Deposition ◽

Surface Recombination Velocity ◽

Strong Increase ◽

X Ray ◽

Recombination Velocity

AbstractWe report on the orientation dependence ((100), (110) and (111) ) of photoluminescence (PL), photoreflectance (PR) and Surface Photo-Voltage (SPV) for sulfur passivated bulk semiinsulating (SI) GaAs. Near band gap PL peak intensities (bound-exciton and acceptor-related) were enhanced following (NH4)2S or S2Cl2 treatment of GaAs for all orientations. The reduction of surface recombination velocity (from PL data) was orientation dependent and especially pronounced for the case of (111)A and (111)B orientations. The effect of thin dielectric layers deposited on S-treated surfaces was also investigated, particularly for (100) and (111)A orientations. SPV data shows a strong increase in the above band gap signal after both Streatment and dielectric film deposition, which was higher than that measured for only S-treated surfaces. PR data showed an increase in the interfacial electric field following deposition of dielectric film. The results of absolute S-surface coverage measurements using particle-induced X-ray emission measurements were correlated with the optical characteristics.

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Surface passivation of germanium by atomic layer deposited Al2O3 nanolayers

Journal of Materials Research ◽

10.1557/s43578-020-00052-x ◽

2021 ◽

Author(s):

Wilhelmus J. H. Berghuis ◽

Jimmy Melskens ◽

Bart Macco ◽

Roel J. Theeuwes ◽

Marcel A. Verheijen ◽

...

Keyword(s):

Surface Passivation ◽

Surface Recombination ◽

Atomic Layer ◽

Extensive Study ◽

Surface Recombination Velocity ◽

Interface Charges ◽

Layer Deposition ◽

Recombination Velocity ◽

Electronic Defects

AbstractSurfaces of semiconductors are notorious for the presence of electronic defects such that passivation approaches are required for optimal performance of (opto)electronic devices. For Ge, thin films of Al2O3 prepared by atomic layer deposition (ALD) can induce surface passivation; however, no extensive study on the effect of the Al2O3 process parameters has been reported. In this work we have investigated the influence of the Al2O3 thickness (1–44 nm), substrate temperature (50–350 °C), and post-deposition anneal (in N2, up to 600 °C). We demonstrated that an effective surface recombination velocity as low as 170 cm s−1 can be achieved. The role of the GeOx interlayer as well as the presence of interface charges was addressed and a fixed charge density $${Q}_{\mathrm{f}}=$$ Q f = −(1.8 ± 0.5) × 1012 cm−2 has been found. The similarities and differences between the passivation of Ge and Si surfaces by ALD Al2O3 prepared under the same conditions are discussed. Graphic Abstract

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Surface Passivation of 4H-SiC for High Current Gain Bipolar Junction Transistors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.615-617.837 ◽

2009 ◽

Vol 615-617 ◽

pp. 837-840 ◽

Cited By ~ 2

Author(s):

Yuki Negoro ◽

Akihiko Horiuchi ◽

Kensuke Iwanaga ◽

Seiichi Yokoyama ◽

Hideki Hashimoto ◽

...

Keyword(s):

High Performance ◽

Surface Passivation ◽

Surface Recombination ◽

Current Gain ◽

Surface Recombination Velocity ◽

Clear Correlation ◽

Bipolar Junction Transistors ◽

High Current ◽

Blocking Voltage ◽

Recombination Velocity

Surface passivation of 4H-SiC has been investigated for high current-gain bipolar junction transistors (BJTs). For the characterization of surface passivation, we have introduced the product “sp•Ls” of a surface recombination velocity (sp) and a surface diffusion length (Ls). The sp•Ls value was obtained by analyzing the I-V characteristics of pn diodes. Both BJTs and pn diodes were fabricated with several passivation methods. We have found clear correlation between the sp•Ls value and the current gain of the fabricated BJTs. Optimizing the surface passivation, we realized high performance BJTs with a current gain of 107 and a blocking voltage VCEO of 950 V.

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Quinhydrone Chemical Passivation of a Silicon Surface for Minority Carrier Bulk-Lifetime Measurements

International Journal of Photoenergy ◽

10.1155/2012/732647 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 3

Author(s):

M. Solcansky ◽

J. Vanek ◽

A. Poruba

Keyword(s):

Silicon Surface ◽

Surface Passivation ◽

Minority Carrier ◽

Surface Recombination ◽

Optimal Solution ◽

Surface Recombination Velocity ◽

Start Up ◽

Chemical Passivation ◽

Recombination Velocity

For the measurement of the minority carrier bulk-lifetime the characterization method MW-PCD is used, where the result of measurement is the effective carrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surface passivation. This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Various solutions are tested on silicon wafers for their consequent comparison. The main purpose is to find optimal solution, which suits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibility of a perfect cleaning of a passivating solution remains from a silicon surface, so that the parameters of a measured silicon wafer will not worsen and there will not be any contamination of the other wafers series in the production after a repetitive return of the measured wafer into the production process. The cleaning process itself is also a subject of a development.

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Effect of low thermal budget annealing on surface passivation of silicon by ALD based aluminum oxide films

Physical Chemistry Chemical Physics ◽

10.1039/c4cp03430a ◽

2014 ◽

Vol 16 (39) ◽

pp. 21804-21811 ◽

Cited By ~ 14

Author(s):

Vandana Vandana ◽

Neha Batra ◽

Jhuma Gope ◽

Rajbir Singh ◽

Jagannath Panigrahi ◽

...

Keyword(s):

Silicon Surface ◽

Surface Passivation ◽

Surface Recombination ◽

Surface Recombination Velocity ◽

Thermal Budget ◽

Fixed Charges ◽

Short Annealing ◽

Recombination Velocity ◽

Low Thermal Budget ◽

Silicon Surface Passivation

Silicon surface passivation is studied using Al2O3 films by the thermal ALD process. A surface recombination velocity of below 10 cm s−1 is realized for short annealing times (∼100 s). As-deposited and annealed films show the presence of positive fixed charges.

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Comparison of Efficiencies of Different Surface Passivations Applied to Crystalline Silicon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.108-109.585 ◽

2005 ◽

Vol 108-109 ◽

pp. 585-590 ◽

Cited By ~ 2

Author(s):

Olivier Palais ◽

Mustapha Lemiti ◽

Jean-Francois Lelievre ◽

Santo Martinuzzi

Keyword(s):

Silicon Surface ◽

Surface Passivation ◽

Crystalline Silicon ◽

Surface Recombination ◽

Surface Recombination Velocity ◽

Phosphorus Diffusion ◽

Type Silicon ◽

Good Surface ◽

Recombination Velocity ◽

P Type

In this work the efficiencies of different surface passivation techniques are compared. This paper emphasizes on the passivation provided by SiNx:H layers that is commonly used in photovolaic industry as surface passivation and anti reflection layer. The method used to evaluate the surface recombination velocity is detailed and discussed. It is shown that light phosphorus diffusion at 850°C – 20 min provides good surface passivation of n-type silicon surface and noticeable passivation of p-type, that can be improved by SiNx:H Layer.

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