Band Bending in Semiconductors: Chemical and Physical Consequences at Surfaces and Interfaces

A review on plasmonic metal⿿TiO2 composite for generation, trapping, storing and dynamic vectorial transfer of photogenerated electrons across the Schottky junction in a photocatalytic system

“…Metal deposited TiO 2 shows an absorption band in the visible region due to surface plasmon resonance (SPR) effect [19]. SPR is a characteristic feature of any metal nanoparticle deposited on semiconductor and this effect arises as a result of collective modes of oscillation of the free CB electrons induced by its interaction with electromagnetic field [20]. At the semiconductor/metal interface a significant redistribution of charge occurs due to the overlap of the wave functions from the two sides, depending on the work function of metal and semiconductor.…”

Silver metalized mixed phase manganese-doped titania: Variation of electric field and band bending within the space charge region with respect to the silver content

“…The CB edge position of anatase is found to be slightly higher compared to that of the rutile phase [55,56]. The work function of the rutile is slightly lower than that of anatase, which causes the energy bands of rutile to bend upwards and energy bands of anatase to bend downwards [16,57]. The established electric fields near the interface makes the electrons move downhill and holes move uphill.…”

“…When m > s the energy bands bend upwards at the interface, and when m < s the energy bands bend downwards. The work function difference between the metal and the semiconductor influences the degree of V BB at the interface [16,[40][41][42][43].…”

“…However in a catalytic system where semiconductor particles with small metal deposits are used as a catalyst which are smaller than 10 nm, finite metal/semiconductor interface model is more relevant [16,47]. In this regard Ioannindes and Verykios have proposed a model based on Schottky approximation.…”

“…The thickness of the depletion layer and space charge region is influenced by the size of the deposited metal nanoparticles and hence the present research attempts an elaborate study on the mechanism of an interfacial electron transfer at the heterojunctions. This research study aimed to understand the various governing factors in this regard which influence the photocatalytic efficiency of surface metal deposited mixed phase titania [16]. Silver was deposited on the surface of Mn-TiO 2 by photo induced deposition method and the percentage of silver was varied from 0.10 to 1.5%.…”