In the present work, the microcrystalline characteristics of KBr thin films have been investigate... more In the present work, the microcrystalline characteristics of KBr thin films have been investigated by evaluating the breadth of diffraction peak. The Wil-liamson–Hall, the Size-Strain plot and the single-line Voigt methods are employed to deconvolute the finite crystallite size and microstrain contribution from the broaden X-ray profile. The texture coefficient and dislocation density have been determined along each diffraction peak. Other relevant physical parameters such as stress, Young's modulus and energy density are also estimated using uniform stress deformation and uniform deformation energy density approximation of Williamson–Hall method.
Performance of cesium iodide (CsI) as a reflective photocathode is presented. Absolute quantum ef... more Performance of cesium iodide (CsI) as a reflective photocathode is presented. Absolute quantum efficiency (QE) measurement of 500 nm thick CsI film has been carried out in the wavelength range of 150 nm to 200 nm. Optical absorbance of 500 nm thick CsI film in the spectral range of 190 nm to 900 nm is analyzed and optical energy band gap is calculated using Tauc plot. To see the dispersive behavior of CsI film, refractive index has been determined by envelop plot of transmittance data, using Swanepoel method. Additional information on morphological and elemental composition results of CsI film, gained by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively are also reported in present work.
We have investigated the influence of water molecule absorption on photoemissive and structural p... more We have investigated the influence of water molecule absorption on photoemissive and structural properties of potassium bromide (KBr) thin film photocathode under humid air exposure at relative humidity 62 ±3%. It is evident from photoemission measurement that the photoelectron yield of KBr photocathode is degraded exponentially with humid air exposed time. Structural studies of the “as-deposited” and “humid air aged” films reveal that there is no effect of relative humidity on film׳s crystalline face centered cubic structure. However, the crystallite size of “humid air aged” KBr film has been increased as compared to “as-deposited” one. In addition, topographical properties of KBr film are also examined by means of scanning electron microscope, transmission electron microscope and atomic force microscope and it is observed that granular characteristic of film has been altered, even for short exposure to humid atmosphere.
In the present work, the microcrystalline characteristics of KBr thin films have been investigate... more In the present work, the microcrystalline characteristics of KBr thin films have been investigated by evaluating the breadth of diffraction peak. The Wil-liamson–Hall, the Size-Strain plot and the single-line Voigt methods are employed to deconvolute the finite crystallite size and microstrain contribution from the broaden X-ray profile. The texture coefficient and dislocation density have been determined along each diffraction peak. Other relevant physical parameters such as stress, Young's modulus and energy density are also estimated using uniform stress deformation and uniform deformation energy density approximation of Williamson–Hall method.
Performance of cesium iodide (CsI) as a reflective photocathode is presented. Absolute quantum ef... more Performance of cesium iodide (CsI) as a reflective photocathode is presented. Absolute quantum efficiency (QE) measurement of 500 nm thick CsI film has been carried out in the wavelength range of 150 nm to 200 nm. Optical absorbance of 500 nm thick CsI film in the spectral range of 190 nm to 900 nm is analyzed and optical energy band gap is calculated using Tauc plot. To see the dispersive behavior of CsI film, refractive index has been determined by envelop plot of transmittance data, using Swanepoel method. Additional information on morphological and elemental composition results of CsI film, gained by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively are also reported in present work.
We have investigated the influence of water molecule absorption on photoemissive and structural p... more We have investigated the influence of water molecule absorption on photoemissive and structural properties of potassium bromide (KBr) thin film photocathode under humid air exposure at relative humidity 62 ±3%. It is evident from photoemission measurement that the photoelectron yield of KBr photocathode is degraded exponentially with humid air exposed time. Structural studies of the “as-deposited” and “humid air aged” films reveal that there is no effect of relative humidity on film׳s crystalline face centered cubic structure. However, the crystallite size of “humid air aged” KBr film has been increased as compared to “as-deposited” one. In addition, topographical properties of KBr film are also examined by means of scanning electron microscope, transmission electron microscope and atomic force microscope and it is observed that granular characteristic of film has been altered, even for short exposure to humid atmosphere.
Uploads
Papers by Richa Rai