Papers by Keyword: Indium Phosphide

Abstract: This study examined the impact of silica-coating on the luminescence characteristics of indium phosphide (InP) nanoparticles. Silica-coated InP nanoparticles were prepared using three different techniques. The first method utilized tetraethoxysilane (TEOS) as the silica source, resulting in the encapsulation of multiple InP nanoparticles within silica spheres. This approach caused a red-shift in the luminescence peak wavelength of the InP colloidal solution post-TEOS coating, compared to the original InP colloidal solution. Conversely, the second method employed tetramethoxysilane (TMOS), resulting in the formation of irregularly shaped silica-coatings on multiple InP nanoparticles, which reduced the red-shift in the luminescence peak wavelength of the silica-coated InP colloidal solution. The third method involved pre-coating InP nanoparticles with TMOS, followed by thickening the silica shells using TEOS. This technique successfully encapsulated multiple InP nanoparticles within silica spheres, maintaining the luminescence peak wavelength of the InP colloid solution post-coating with TMOS and TEOS nearly identical to that of the original solution. This method merged the advantageous outcomes of the first two methods. Additionally, silica spheres containing InP nanoparticles synthesized using both TMOS and TEOS exhibited the highest luminescence intensity. In summary, this study introduces a novel approach in nanoparticle engineering, enhancing the functional properties of InP nanoparticles and expanding their potential applications in optoelectronic devices.

Abstract: The density functional theory is applied for examining the electronic structure and spectroscopic properties for InP wurtzite molecules and nanocrystals. In this paper we present calculations of the energy gap, bond lengths, IR and Raman spectrum, reduced mass and force constant. The results of the presented work showing that the InP’s energy gap was fluctuated about to experimental bulk energy gap (1.49 eV). Results of spectroscopic properties including IR and Raman spectrum, reduced mass and force constant as a function of frequency were in accordance with the provided experimental results. In addition, the study of the Gibbs free energy proved the stability phase of InP wurtzoids against transition to InP diamondoids structure.

Abstract: III-V semiconductor compounds are increasingly studied for their interesting properties in the fields of microelectronics, optoelectronics, infrared detectors or solar cells. Firstly, they are promising candidates to replace silicon as a channel material. As CMOS scales beyond the 22 nm node it is widely expected that new higher mobility channel materials such as In_xGa_1-xAs will have to be introduced [1]. On the other hand, III-V materials have a direct bandgap making them useful for optoelectronic devices or high-efficiency multijunction photovoltaic cells. For these applications InP, GaAs and their alloys as In_xGa_1-xAs and Ga_xIn_1-xP are investigated [2]. Depending on the targeted applications, several possible integration routes of III-V components could be considered: from 100 mm III-V substrates to III-V epitaxial layers grown on 300 mm silicon wafers as well as a few square centimetres chips bonded on 200 or 300 mm carrier wafers for photonics applications. In all cases, the manufacturing of devices requires a multitude of wet chemical steps including selective etching steps (from a few nanometres up to several microns) and cleaning steps (metallic or particles contamination removal).

Abstract: Compound semiconductors based on group III and V elements of the periodic system have high charge carrier mobility and are, therefore, candidates for channel material in future CMOS devices [1]. In order to design wet chemical solutions that lead to appropriate surface pre-conditioning and allow for nanoscale processing and minimal substrate loss, a thorough understanding of the interactions between the substrate and the chemical solutions is needed and the basic etching mechanisms needs to be resolved. The focus of this research is on InP in acidic solutions. ESH aspects are also considered.

Abstract: Ridge waveguides in InP-based heterostructures were fabricated by inductively coupled plasma (ICP) reactive ion etching using chlorine-based gases. The heterostructures included a series of 6 quantum wells (QW) made from quaternary material GaxIn1-xAsyP1-y emitting at 1.55 µm, and located very close to the surface (first QW at 250 nm). The etched structures (different widths and depths) were characterized at room and low temperature (80 K) by spectrum image cathodoluminescence (CL). The signature of the QWs was used to investigate effects induced by the dry etching process. Defects (or defect complexes) were observed, especially close to the edges of the etched structures, as well as a blue-shift of the CL lines from the nominal position. This was attributed to some intermixing of the QWs. Intermixing is induced by the defects that form during the dry etching process. The origin of these defects is discussed, taking into account previous studies performed on similar samples, except for the fact that the etched material was bulk InP instead of QW layers.

Abstract: It is of great significance to study on the dislocation density distribution of different types of doped indium phosphide (InP) crystal wafers for fabricating high-quality InP single crystal with low dislocation density. In the paper, a new etched pits density mapping (EPD mapping) measurement is introduced to measure the dislocation density distribution of the S-doped, Fe-doped and non-doped InP wafers pulled by high-pressure liquid encapsulated Czochralski (HP-LEC) technique. Test results show that in the three types of InP wafers， the S-doped InP wafer’s dislocation density is lowest and uniformity is best; the non-doped InP wafer’s dislocation density is maximum and uniformity is the worst; the Fe-doped InP wafer’s dislocation density and uniformity are between the S-doped and non-doped InP wafers. In the paper, the measurement results are analyzed in detail also from the faces of the doping and crystal growth process and thermodynamic mechanism. This study shows that in addition to traditional methods, using reasonable doping process can also effectively reduce the dislocation in the crystal, enhance the lattice strength and improve the uniformity of the InP single crystal.

Abstract: In this paper, current-voltage (i-Vg) results from different kinds of n-type InP Schottky diodes are reported. The diodes were fabricated on an unintentionally doped n-type (100) indium phosphide substrate, and the i-Vg characteristics were measured in the temperature range 100 300 K. For the ideality factor, n always exhibited a small (1) but continuous increase with the voltage. At higher forward voltage, slightly higher values of n were due to series resistance effect; in other words, the interface state density always remained small. However, it was possible to obtain some information in the case of discrete interface traps. It was shown that i-Vg measurements can be used as a fast method to determine the densities of the interface states when they equilibrate with the semiconductor.

Abstract: Positron annihilation lifetime (PAL) spectroscopy，photo-induced current transient spectroscopy (PICTS) and thermally stimulated current (TSC) have been employed to study the formation of compensation defects and their evolvement under iron phosphide (IP) ambience or pure phosphide (PP) ambience. In the formation of IP SI-InP, the diffusion of Fe atoms suppresses the formation of some open-volume defects. As to PP SI-InP, VInH4 complexes dissociate into acceptor vacancies VInHn(n-3)(n=0,1,2,3), which compensate residual donor type defects and make the sample semi-insulating. Electron irradiation-induced deep level defects have been studied by TSC in PP and IP SI-InP, respectively. In contrast to a high concentration of irradiation-induced defects in as-grown and PP annealed InP, IP SI-InP has a very low concentration of defects.