This paper reports the formation and properties of hydrogenated amorphous carbon (a-C: H) films having embedded
nanoparticles deposited by cathodic jet carbon arc (CJCA) technique in absence of magnetic field. The films have been
characterized by XRD, HRTEM, XPS, dark conductivity, activation energy, optical band gap, residual stress, hardness,
elastic modulus and plastic index parameter. The properties evaluated of a-C: H films having embedded particles have
been compared with that of undoped and nitrogen doped a-C films having embedded nanoparticles deposited by CJCA
technique. All the properties of a- C films studied are found to depend on the gaseous environment used during the
deposition of the films. These a-C films having embedded nanoparticles act as hard coating materials.
Heterojunction solar cells have shown a promising comparable efficiency with the advantage of lower fabrication
cost compared to the crystalline solar cells. In this paper, an attempt has been made to simulate the heterojunction
structure and HIT structure using AMPS-1D software by applying various approaches. The simulation parameters of
these structures are varied for cell efficiency, quantum efficiency, charge carrier concentration and temperature
stability to achieve higher efficiency. The final solar cell parameters have been achieved about 20% for
heterojunction and 23% for HIT cells. The effects on intrinsic and extrinsic characteristics of doped layers are
discussed for these efficiencies.
This paper reports the formation and optical properties of amorphous carbon film having embedded
nanoparticles deposited by anodic jet carbon arc technique (AJCA). The films deposited have been
characterized by x-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), and
scanning electron microscope (SEM) and spectroscopy ellipsometry (SE) measurements. XRD pattern
exhibits dominantly an amorphous nature of film. HRTEM investigation shows initially the amorphous
structure. However, on closer examination nanoparticles were found to be embedded in the amorphous
matrix. The effect of substrate bias and the magnetic field on the optical constants evaluated from SE have
been studied. On comparison of deposition condition with and without magnetic field used in growing a-C
films there is a change in the values of optical constants.
In this work, self bias variation, nitrogen introduction and oxygen plasma (OP) treatment approaches have been used for
tailoring the band gap of hydrogenated amorphous carbon (a-C:H) thin films. The band gap of a-C:H and modified a-
C:H films is varied in the range from 1.25 eV to 3.45 eV, which is found to be nearly equal to the full solar spectrum (1
eV- 3.5 eV). Hence, such a-C:H and modified a-C:H films are found to be potential candidate for the development of full
spectrum solar cells. Besides this, computer aided simulation with considering variable band gap a-C:H and modified a-
C:H films as window layer for amorphous silicon p-i-n solar cells is also performed by AFORS-HET software and
maximum efficiency as ~14 % is realized. Since a-C:H is hard material, hence a-C:H and modified a-C:H films as
window layer may avoid the use of additional hard and protective coating particularly in n-i-p configuration.