The mechanism of charge carrier generation at the TiO₂—n-Si heterojunction activated by gold nanoparticles

Abstract

Photo-induced current through nanocomposite heterojunction structures consisting of a TiO 2 coating activated with embedded gold nanoparticles on top of Si, SiO 2 , and columnar structured SiO 2 is studied. The highest photo-activity in the visible part of the spectrum is found in the composite containing pillar-like silicon dioxide nanostructures. Experimental results were qualitatively explained on the basis of Franz-Keldysh effect taking into account the effects of electrical inhomogeneities appearing at charged nanoparticles. It is established that processes at the interface between silicon and noble metal nanoparticles play an important role in charge carrier photo-generation which opens a new opportunity to tune the photo-response of a nanocomposite via changing heterostructure topology.

Optimizing charge transport and band-offset in silicon heterojunction solar cells: impact of TiO2 contact deposition temperature

“…At low voltages, the current through a TiO 2 film is small and only slightly affected by voltage changes, which arise due to the low intrinsic carrier concentration in TiO 2 and a negatively biased Schottky barrier between the metal contact and TiO 2 . However, as the applied voltage increases, tunnel breakdown occurs in the TiO 2 film, leading to a sudden increase in current density and an increase in the J o [44].…”

Thermal Management in Neuromorphic Materials, Devices, and Networks

“…Neural network 3D dynamic functional White matter ≈ 0.48 [133] Gray matter ≈ 0.55 [133] White matter ≈ 0.5 [133] Gray matter ≈ 0.8 [133] Information processing ≈ 1000 Tb Vascular network 3D static centralized Blood ≈ 0.52 [133] Blood ≈ 1.3 [133] Cooling/ Energy delivery Neuromorphic network 2D static crossbar TiO 2 ≈ 5.8 [134][135][136] MnO 2 ≈ 4 [134,137] WO 3 ≈ 1.6 [138] ZnO ≈ 40 [139] CuO ≈ 33 [141] Graphene ≈ 4 × 10 3 [143] Ta 2 O 5 ≈ 0.7 [145] HfO 2 ≈ 0.5-1 [147] VO 2 ≈ 5-20 [149] V 2 O 3 ≈ 3-6 [151] V 3 O 5 ≈ 2-5 [151] TiO 2 ≈ 10 3 [134][135][136] MnO 2 ≈ 10 3 [134,137] WO 3 ≈ 10 −2 to 10 [138] ZnO ≈ 7 × 10 −5 [140] CuO ≈ 1 [142] Graphene ≈ 3 × 10 5 [144] Ta 2 O 5 ≈ 10 −4 to 10 −8 [146] HfO2 ≈ 10 −13 [148] VO 2 ≈ 10 to 10 3 [150] V 2 O 3 ≈ 10 −2 to 10 6 [152] V 3 O 5 ≈ 10 −1 to 10 7 [153] Information processing ≈ 1 Tb…”

Conduction Band Discontinuity in n-type Si/TiO2 Heterojunction Interfaces

“…Moreover, compared with TiO 2 SEs to a Cr-doped TiO 2 sample showed an increase in photovoltage, but the sample is not sustainable and a reproducibility problem occurred. 3 The TiO 2 and n-type or p-type Si heterojunction interface attracted much interest and various modifications have been made such as n-type Si/TiO 2 heterojunctions activated by gold nanoparticles 4 and p-type Si/TiO 2 heterojunctions by a polyphenylene interlayer. 5 Perego et al were probably the first to analyze the band alignment between TiO 2 and Si by translating the obtained XPS data.…”