I have synthesized SrZrO3 oxide perovskite and the band gap was calculated 5.8eV. Please suggest me how to calculate HOMO and LUMO values???
Dear colleague Khursheed Ahmad
Have a nice time and good day.
Herein find beside the following text four attached papers give you more details about HOMO-LOMO gap identification and how to calculate it optically. next you will have a short abbreviation was prepared about HOMO-LOMO (bonds and gaps) and the reference were cited. have a special look to paper No.1
Generally at the beginning of the 21st century, new electronics revolution that has become possible due to the development and understanding of a new class of materials, commonly known as Organic Semiconductors. In this class of materials, the molecular orbitals split into bonding and anti-bonding states. The bonding states are the highest occupied molecular orbital (HOMO; π−orbitals) and anti-bonding states are the lowest unoccupied molecular orbital (LUMO; π*−orbitals). This splitting is due to the interaction of adjacent chains along given directions yields the transfer integral to be used for the description of hole (electron) transport in these directions [1-4]. HOMO level is analogous to the term valence band, associated with inorganic semiconductors, and used to imply a lower set of energy levels, completely filled with electrons. Similarly, LOMO level can be compared to the conduction band, a term used to explain a vacant or partially occupied set of many closely spaced electronic levels in which the electrons are free to move [1-4]. The higher the HOMO (LUMO) bandwidth, the higher the expected hole (electron) mobility. It turns out that, at low temperature, the charge transport in a number of organic crystals and highly organized thin films can be described in a band-like regime similar to that in inorganic semiconductors. In that case, the difference or the total widths and shapes of the valence and conduction bands formed by the interaction of the HOMO and LUMO levels of the π-conjugated chains, respectively, determine the hole and electron mobilalities or the band gap of the material [1-4].
[1] J.H. Schon, C. Kloc, B. Batlogg, Phys. Rev. Lett. 86, 3843 (2001).
[2] J. L. Bredas, J. P. Calbert, D. A. da Silva Filho, J. Cornil,
PNAS 99, 5804 (2002).
[3] N. Lee, H. Shin, Y.J. Kim, C. Kimd, S. Suhd. Rev. Roum. Chim.,
55, 627 (2010).
[4] M. Dongol A. El-Denglawey A. F. Elhady, A. A. Abuelwafa
Appl. Phys. A (2015) 118:345–351
Well you already know the HOMO-LUMO gap (band gap), so you only need to measure one of these. I think UPS or XPS methods can be used to find the absolute energy difference between the valence band (HOMO) and the vacuum level.
Dear colleague Khursheed Ahmad
Have a nice time and good day.
Herein find beside the following text four attached papers give you more details about HOMO-LOMO gap identification and how to calculate it optically. next you will have a short abbreviation was prepared about HOMO-LOMO (bonds and gaps) and the reference were cited. have a special look to paper No.1
Generally at the beginning of the 21st century, new electronics revolution that has become possible due to the development and understanding of a new class of materials, commonly known as Organic Semiconductors. In this class of materials, the molecular orbitals split into bonding and anti-bonding states. The bonding states are the highest occupied molecular orbital (HOMO; π−orbitals) and anti-bonding states are the lowest unoccupied molecular orbital (LUMO; π*−orbitals). This splitting is due to the interaction of adjacent chains along given directions yields the transfer integral to be used for the description of hole (electron) transport in these directions [1-4]. HOMO level is analogous to the term valence band, associated with inorganic semiconductors, and used to imply a lower set of energy levels, completely filled with electrons. Similarly, LOMO level can be compared to the conduction band, a term used to explain a vacant or partially occupied set of many closely spaced electronic levels in which the electrons are free to move [1-4]. The higher the HOMO (LUMO) bandwidth, the higher the expected hole (electron) mobility. It turns out that, at low temperature, the charge transport in a number of organic crystals and highly organized thin films can be described in a band-like regime similar to that in inorganic semiconductors. In that case, the difference or the total widths and shapes of the valence and conduction bands formed by the interaction of the HOMO and LUMO levels of the π-conjugated chains, respectively, determine the hole and electron mobilalities or the band gap of the material [1-4].
[1] J.H. Schon, C. Kloc, B. Batlogg, Phys. Rev. Lett. 86, 3843 (2001).
[2] J. L. Bredas, J. P. Calbert, D. A. da Silva Filho, J. Cornil,
PNAS 99, 5804 (2002).
[3] N. Lee, H. Shin, Y.J. Kim, C. Kimd, S. Suhd. Rev. Roum. Chim.,
55, 627 (2010).
[4] M. Dongol A. El-Denglawey A. F. Elhady, A. A. Abuelwafa
Appl. Phys. A (2015) 118:345–351
Dear Khursheed thank you for asking such an important question.
and Dear A. Eldenglawey and Manuel Schnabel Sir, thank you for answering in a very nice way and detail.
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