2D Carrier Localization at the Wurtzite-Zincblende Interface in Novel Layered InP Nanomembranes

Abstract

The successful application of semiconductor nanostructures in devices has attracted intense interest in their carrier dynamics. Here an in-depth investigation of the carrier dynamics in novel layered InP nanomembranes with a large area of atomically sharp wurtzite-zincblende (WZ-ZB) interface is conducted for the first time by using various spectroscopic techniques. Two kinds of type II transitions in these nanomembranes are observed, which are from the ZB/WZ type II planar interface and stacking faultinduced ZB segments in the WZ phase layer. A strong two-dimensional carrier localization effect in the flat type II interface is demonstrated at low temperatures. As the excitation fluence increases, the occurrence of state filling can play an important role in the emission energy and lifetime of this type II transition. Thermal transfer of carriers from the type II interface 2D localization to the ZB conduction band results in the quenching of type II transitions at room temperature. Interesting novel emission polarization behaviors of different transitions in this InP nanomembrane are also highlighted. The polarization direction of the WZ and ZB emissions, as well as two kinds of type II transitions, are found to be perpendicular to each other. This study thus provides a deeper insight into the type II transitions in semiconductor nanostructures.

n‐SnOx as a Transparent Electrode and Heterojunction for p‐InP Nanowire Light Emitting Diodes

“…The position of this peak is at ≈920 nm at 1 mA of current injection, which is consistent with reported values. [49] Moreover, as the injected current increases, a blue shift in the peak is observed similar to that reported by Su et al confirming this peak originates from the interface of NW (WZ) and InP substrate (ZB). [49] Another possibility of this peak could be the mixed-phase structure in the NWs.…”

“…[49] Moreover, as the injected current increases, a blue shift in the peak is observed similar to that reported by Su et al confirming this peak originates from the interface of NW (WZ) and InP substrate (ZB). [49] Another possibility of this peak could be the mixed-phase structure in the NWs. However, we rule out this case here as it has previously been reported that for the above-mentioned growth conditions, the NWs have a pure WZ phase.…”

“…[48] The lowest energy peak (ZB/WZ), is related to the type II transition from ZB to WZ interface between the NWs and substrate. [49] Figure 3e (top) represents the ratio of integrated EL intensity of each peak divided by the total intensity of the EL spectra. Lorentzian fitting was performed to calculate the area under the curve corresponding to each peak.…”

“…[ 48 ] The lowest energy peak (ZB/WZ), is related to the type II transition from ZB to WZ interface between the NWs and substrate. [ 49 ]…”

Asymmetric Broadening and Enhanced Photoluminescence Emission in ZnO Due to Electron–Phonon Coupling

“…At low temperatures, the carriers are highly localized, and electronic transitions strongly are coupled to lattice vibrations. 38 The quantum dissipation effect of the phonon bath leads to the asymmetric and broad emission band, which are consistent with the sharp rise at the blue edge and long tail at the red edge observed by PL. Thus, photons with a wide range of energies possess an indistinguishable dynamic feature, verifying the phenomenon in TRPL (Figure 2c,d).…”