In Schottky emission the band is lowered due to application of externally applied electric field to thermally activated surface.However generally when a metal surface in brought in contact with insulator/semiconductor the band is lowered due to difference in Fermi levels or when Fermi levels are aligned together.
So is there any fundamental difference between band bending and band lowering?
Article Schottky barrier formation and band bending revealed by firs...
https://www.researchgate.net/post/Is_the_Schottky_barrier_lowering_model_from_Synopsys_TCAD_correct_Where_are_its_limits_except_the_ones_from_the_manual_Are_there_any_experiences
https://pubs.acs.org/doi/abs/10.1021/cr3000626?src=recsys&journalCode=chreay
https://thesis.library.caltech.edu/8032/1/GleasonRohrer2013thesis.pdf
Dear Kapil:
The initial band alignment or lowering at Vg = 0 is due to the Schottky barrier height but due to Fermi level alignment, at equilibrium for n-type silicon Schottky diode or p-type silicon Schottky diode additionally band bending takes place at the surface extending to the bulk where the reverse bias field exists. This band bending is characterized by Vbi or built-in potential. Your idea that when we put gate voltage on metal, metal work function or metal energy band is modulated, this is band lowering on the metal side affecting barrier height, but you probably missed the point that band bending is due to concentration of spatial charge in a depletion region formed from the silicon surface to quasi neutral bulk in the silicon substrate which we use Poisson's equation to solve reverse biased field, Vbi and spatial variation of band bending up or down considering the type of substrate. See the link for clarification: http://in.ncu.edu.tw/ncume_ee/SchottkyDiode.htm
If my answer is useful, please recommend my answer as recommendation helps to uplift the ResearchGate profile of the responder.
Sincerely,
Dr. Nabil Shovon Ashraf.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Semiconductor