Revealing the Photocharge-Transfer Mechanism at Manganite-Buffered LaAlO₃/SrTiO₃ Interfaces by Giant Photoresponse

Abstract

The photoinduced phase transition at complex oxides remains one of the very important issues because of the emergent physics and potential applications. In particular, the mechanism of charge transfer at interfaces under irradiation is challenging. Herein, the photoinduced properties of manganite-buffered LaAlO 3 /SrTiO 3 interfaces with different thicknesses of the buffer layer are systematically investigated. The giant photoresponse is observed, and its relative change in resistance is about 6.24 × 10 6 % at T = 20 K for the sample with a buffer layer thickness of 4.8 nm. Moreover, the transition temperature is enhanced by increasing the thickness of the buffer layer. More importantly, the dead layer effect at the interfaces has been suppressed by using light. All these results are attributed to the charge transfer because of the octahedral tilting at low temperatures and provide a new kind of oxide-based optical devices, such as ultraviolet detectors. This piece of work will pave the way toward twodimensional electron gas-based optoelectronic devices.

Semiconducting eutectic materials for photocatalysis and photoelectrochemistry applications: a perspective

“…95,104,105,[120][121][122] On the other hand, interfaces found at the junction of the two materials also display remarkable properties. 123,124 These interface-based heterojunctions have also been utilized for solar energy devices where interfaces are main places of charge-transfer. 81,125 Such interfaces can be made using the m-pulling method that can be visible up to the surface and provides profound control of the active sites of heterojunctions at the surface leading to further modulation of PEC properties.…”

Manipulation of 2DEG at double-doped high-entropy heterointerfaces

“…[14][15][16][17][18][19][20][21][22][23] These complex oxide interfaces provide combined efficiency of different factors, like crystal lattice, orbital, and spin, [24][25][26] which explain the diversity of physical phenomena and sensitive response towards external stimuli. To manipulate the 2DEG in such oxide interfaces, some research studies have adopted different doping methods, like structural modulation by introducing a buffer layer, [27][28][29][30][31][32] and they proved their good capability. However, the discontinuity in the structure and component can naturally lead to some limitations, like localized trap or scattering centers for carriers.…”

Effect of Thermal Conductivity of Substrate on the Giant Persistent Photoconductivity of Vanadium Dioxide Device

“…For the heterostructures system, the GPPC is attributed to the presence of potential barriers at surface/interfaces that separate the photoinduced electron-hole pair in long period. [1][2][3][4][5][6][7] In the case of the III-V semiconductor compounds, the potential barrier is ascribed to large lattice difficult to generate GPPC with a short single pulse laser VO 2 device on substrate of high thermal conductivity. In fact, most of VO 2 film devices have been fabricated on Al 2 O 3 substrate which has a high thermal conductivity, [17,18] preventing the observation of GPPC in VO 2 /Al 2 O 3 device.…”

“…For the heterostructures system, the GPPC is attributed to the presence of potential barriers at surface/interfaces that separate the photoinduced electron–hole pair in long period. [ 1–7 ] In the case of the III–V semiconductor compounds, the potential barrier is ascribed to large lattice relaxation which is related to the trapping electron at the defect state during photoexcitation. [ 8 ] Under these charge‐separation models, the photocarrier density ( n p ) increases with the photoirradiation time and the photon flux.…”