Electronic And Structural Properties Of Bialkali Antimonide Photocathode Materials

Electronic band structure theories took a best leap with the introduction of density functional theory into quantum mechanics. later so many methods emerged out of it and one regarding the successful methods is the Linear Mu n-Tin Orbital theory with Atomic Sphere Approximation. This is a first principle approach to the electronic srtucture problemwhich is simple, transparent, elegant and fast. This metho d is used to read the electronic structure of bialkali antimonide photocathode materials. The e ect of compression on these fabrics is studied by creating use of the Murnaghan equation of state.

The band structure and the density of states for the 3 compounds a are dipicted below. The significant featureof the band sructure of these compounds is that the valence band is comprised of 3 sub-bands separated by a huge gap of about 6. This implies that these compounds have chemical bonds of highly ionic nature. THe bulk modulus values of these fabrics display that they can with no problems be compressed and one can expect a structural transi-tion below moderate pressures. Comparing the band structures and density of states with the correspond-ing binary compounds likeandit is clean that the presence ofthe new alkali atom causes the six states to contribute to the conduction band.

If the new alkali atom has very fewer electro negativity then its contribution shall be very high to change the binary fabric structure. The experimental bandgap of is two 1hich reduces to 0. 95 in and the experimental bandgap of is 0 9which re-duces to 0 52 and 0 66 inandespectively. Thus the presence of extra alkali atom tries to reduce the band gap.