II-VI Material Integration With Silicon for Detector and PV Applications

MRS Advances ◽  
2016 ◽  
Vol 1 (50) ◽  
pp. 3391-3402 ◽  
Author(s):  
T.A. Gessert ◽  
E. Colegrove ◽  
B. Stafford ◽  
R. Kodama ◽  
Wei Gao ◽  
...  

ABSTRACTHeteroepitaxial growth of high-quality II-VI-alloy materials on Si substrates is a well-established commercial growth process for infrared (IR) detector devices. However, it has only recently been recognized that these same processes may have important applications for production of high-efficiency photovoltaic devices. This submission reviews the process developments that have enabled effective heteroepitaxy of II-VI alloy materials on lattice-mismatched Si for IR detectors as a foundation to describe recent efforts to apply these insights to the fabrication of multijunction Si/CdZnTe devices with ultimate conversion efficiencies >40%. Reviewed photovoltaic studies include multijunction Si/CdZnTe devices with conversion efficiency of ∼17%, analysis of structural and optoelectrical quality of undoped CdTe epilayer films on Si, and the effect that a Te-rich growth environment has on the structural and optoelectronic quality of both undoped and As-doped heteroepitaxial CdTe.

2014 ◽  
Vol 778-780 ◽  
pp. 230-233
Author(s):  
Yukimune Watanabe ◽  
Tsuyoshi Horikawa ◽  
Kiichi Kamimura

The carbonized layer for a buffer layer strongly influences the crystalline quality of the 3C-SiC epitaxial films on the Si substrates. The growth mechanism of the carbonized layer strongly depended on the process conditions. The surface of silicon substrate was carbonized under the pressure of 7.8 × 10-3 Pa or 7.8 × 10-2 Pa in this research. Under the relatively low pressure of 7.8 × 10-3 Pa, the carbonized layer was grown by the epitaxial mechanism. The crystal axis of the carbonized layer grown under this pressure was confirmed to coincide with the crystal axis of the Si substrate from the results of the selected area electron diffraction (SAED) analysis. Under the relatively high pressure condition of 7.8 × 10-2 Pa, the carbonized layer was grown by the diffusion mechanism. The result of the SAED pattern and the XTEM image indicated that this layer consisted of small grainy crystals and their crystal axes inclined against the growth direction. It was confirmed that the crystalline quality of the SiC film deposited on the carbonized layer grown by the epitaxial mechanism is better than that deposited on the layer grown by the diffusion mechanism.


2020 ◽  
Vol 8 (3) ◽  
pp. 883-888 ◽  
Author(s):  
Yuan Li ◽  
Zhiheng Xing ◽  
Yulin Zheng ◽  
Xin Tang ◽  
Wentong Xie ◽  
...  

High quantum efficiency LEDs with InGaN/GaN/AlGaN/GaN MQWs have been demonstrated. The proposed GaN interlayer barrier can not only increase the concentration and the spatial overlap of carriers, but also improve the quality of the MQWs.


2012 ◽  
Vol 717-720 ◽  
pp. 193-196 ◽  
Author(s):  
Valdas Jokubavicius ◽  
Björn Lundqvist ◽  
Philip Hens ◽  
Rickard Liljedahl ◽  
Rositza Yakimova ◽  
...  

Heteroepitaxial growth of 3C-SiC on 0.8 and 1.2 degree off-oriented 6H-SiC substrates was studied using a sublimation growth process. The 3C-SiC layers were grown at high growth rates with layer thickness up to 300 µm. The formation and the quality of 3C-SiC are influenced by the off-orientation of the substrate, the growth temperature (studied temperature range from 1750 °C to 1850°C), and the growth ambient (vacuum at 5*10-5mbar and nitrogen at 5*10-1mbar). The largest domains of 3C-SiC and the lowest number of double positioning boundaries were grown using nitrogen ambient and the highest growth temperature. The combined use of low off-axis substrate and high growth rate is a potential method to obtain material with bulk properties.


2008 ◽  
Vol 600-603 ◽  
pp. 243-246 ◽  
Author(s):  
Ruggero Anzalone ◽  
Andrea Severino ◽  
Giuseppe D'Arrigo ◽  
Corrado Bongiorno ◽  
Patrick Fiorenza ◽  
...  

The aim of this work is to improve the heteroepitaxial growth process of 3C-SiC on Si substrates using Trichlorosilane (SiHCl3) as the silicon growth precursor. With this precursor it has been shown that it is possible to simultaneously increase the growth rate of the process and avoid the nucleation of silicon droplets in the gas phase. Growth experiments were conducted on three (3) Si substrate orientations in order to assess the impact of the Si substrate on the resulting 3C-SiC film. X-ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) analysis show the important role of the substrate orientation for the growth process. The different orientation of the substrate modifies the morphology of the 3C-SiC crystalline structure, mostly by changing the density of micro-twins and stacking faults inside the film.


2003 ◽  
Vol 784 ◽  
Author(s):  
C. W. Hubbard ◽  
M. W. Cole ◽  
M. Ervin ◽  
M. Wood

ABSTRACTThe use of pyroelectric thin films in uncooled IR detectors has many advantages over the present IR detector technology, which requires extensive cooling for operation. These advantages include reduced weight, reduced footprint, reduced complexity, increased reliability, and decreased maintenance. Ba1-xSrxTiO3 (BST), based thin films are ideal candidates for use in these devices due to their tailorable materials properties. These properties include a high dielectric constant, low dielectric loss, high electrical resistivity, as well as a high pyroelectric constant. BST thin films were doped with Mg in varying amounts, from 0 to 20mol%. The thin films were deposited via metalorganic solution deposition (MOSD) on Pt/Ti/SiO2/Si substrates. Annealing temperatures ranged from 500 to 750 °C. The films were characterized for structural, microstructural, compositional, surface morphological, dielectric and insulating properties. Glancing angle x-ray diffraction (GAXRD) was used to determine crystallinity, phase formation and film orientation. Field emission scanning electron microscopy (FESEM) and cross sectional transmission electron microscopy (TEM) were employed to access surface morphology and microstructure. The Materials Detectivity Figure of Merit (FOM), D*, [D*=pi/(CV(ε0εrtanδ)1/2] was used to evaluate the film's detectivity response. Our results show that undoped Ba60Sr40TiO3, with a value D*= 0.08 (cm3/J)1/2, appears to out perform Pb based pyroelectric thin films, thus making it a viable candidate for IR pyroelectric detector applications.


2019 ◽  
Author(s):  
liu jinan

We have investigated growth of InAs on Si substrates by metal organic chemical vapor deposition. The main investigation is the effect of incorporating more nucleation layers into the growth process. The addition of more nucleation layers clearly correlates with the surface morphology and quality of the InAs layer. Morphological and structural characterizations prove that a perfect quality InAs layer is achieved by incorporating five nucleation layers.


Author(s):  
Budi Astuti ◽  
Shaharin Fadzli Abd Rahman ◽  
Masahiro Tanikawa ◽  
Mohamad Rusop Mahmood ◽  
Kanji Yasui ◽  
...  

Heteroepitaxial growth of silicon carbide (SiC) on graphene/SiO<sub>2</sub>/Si substrates was carried out using a home-made hot-mesh chemical vapor deposition (HM-CVD) apparatus. Monomethylsilane (MMS) was used as single source gas while hydrogen (H<sub>2</sub>) as carrier gas. The substrate temperature, tungsten mesh temperature, H<sub>2</sub> flow rate and distance between mesh and substrate were fixed at 750 °C, 1700 °C, 100 sccm and 30 mm, respectively. The growth pressures were set to 1.2, 1.8 and 2.4 Torr. The growth of 3C-SiC (111) on graphene/SiO<sub>2</sub>/Si were confirmed by the observation of θ-2θ diffraction peak at 35.68°. The diffraction peak of thin film on graphene/SiO<sub>2</sub>/Si substrate at pressure growth is 1.8 Torr is relatively more intense and sharper than thin film grown at pressure growth 1.2 and 2.4 Torr, thus indicates that the quality of grown film at 1.8 Torr is better. The sharp and strong peak at 33° was observed on the all film grown, that peak was attributed Si(200) nanocrystal. The reason why Si (200) nanocrystal layer is formed is not understood. In principle, it can’t be denied that the low quality of the grown thin film is influenced by the capability of our home-made apparatus. However, we believe that the quality can be further increased by the improvement of apparatus design. As a conclusion, the growth pressures around 1.8 Torr seems to be the best pressures for the growth of heteroepitaxial 3C-SiC thin film.


1989 ◽  
Vol 145 ◽  
Author(s):  
Masafumi Yamaguchi ◽  
Susumu Kondo

AbstractHeteroepitaxial growth of GaAs, InP, GaP and InGaP on Si substrates is studied using MOCVD (Metal-Organic Chemical Vapor Deposition). High qgaliti GaAs films on Si, with a dislocation density of about 106 cm−2, are obtained by combining strained- layer superlattice insertion and thermal cycle annealing. Reduction of dislocation density in the III-V compounds on Si is discussed based on a simple model, where dislocation annihilation is assumed to be caused by dislocation movement under thermal and misfit stress. As a result of dislocation density reduction, high-efficiency GaAs-on-Si solar cells with total-area efficiencies of 18.3% (AMO) and 20% (AM1.5), and red and yellow emissions from InGaP-on-Si light-emitting diodes (LEDs) have been realized.


2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Ho-Jun Lee ◽  
Kye-Jin Lee ◽  
Kwang-Yong Choi ◽  
Jung-Hyun Eum ◽  
Dong-Kun Lee ◽  
...  

The recent development of dielectric microsphere lithography has been able to open up new means of performing simple and easy patterning on the semiconductor surfaces. Here, we report uniform and high-density arrays of microspheres using a solution-based spin-coating method. The arrays of microspheres were used for etching mask to form the arrays of III-nitride microrods. By regrowing GaN layer on the microrod structures, high-quality GaN layer was achieved in terms of surface morphology as well as XRD characterization. To apply the advantages such as improved crystal quality and light extraction enhancement, light-emitting diodes (LEDs) were grown and then fabricated. The regrown LEDs with microspheres showed much improved optical output power and forward voltage characteristics in the same current injection. Therefore, we believe that this approach is quite useful for the development of high efficiency LEDs for future lighting.


Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.


Sign in / Sign up

Export Citation Format

Share Document