A film stripping method that allows for liquid phase exfoliation assisted by spin coating polymethyl methacrylate has been investigated, resulting in a two‐inch hexagonal boron nitride (hBN) film to be fully stripped and then transferred. A number of key factors that can influence the stripping and the transferring process of the films grown by sputtering have been systematically analyzed, including different solutions, different concentration of solution and different thickness of films. The morphology and properties of the hBN films before and after stripping have been characterized. The band edge absorption peak of the transferred film is 229 nm and the corresponding optical band gap is 5.50 eV. Such transferred hBN films have been fabricated into transparent resistive switching devices on indium‐tin‐oxide glass, demonstrating a constant resistance window of ≈102 even under different applied voltages. This work systematically studies the stripping process, characterizes the transferred films, and explores the application in the field of resistance switching, which lay a foundation for the further application of hBN materials in optoelectronic devices.

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We demonstrated a method to obtain super flexible LEDs, based on high quality pyramid arrays grown directly on sapphire substrates. Laser lift-off (LLO) and dual transfer processes were applied to transfer pyramid arrays face up onto the flexible substrates, which is more efficient than back light emission. Ag grid and Ag nanowires were employed as the electrical connection. No significant performance reduction appeared until the device reached a curvature radius of 0.5 mm. The performance reduction results from cracks appearing at the junction of the Ag grid, which can be improved by replacing the Ag grid with a strip electrode.

A 3D ITO nanowire network with high quality by using polystyrene as an assisted material has been prepared, demonstrating superior optoelectronic performances with a sheet resistance of 193 Ω/sq at 96% transmission. Both remarkable flexibility tested under bending stress and excellent adhesion applied on special terrain substrate have been achieved. This method has led to a full coverage of micro-holes at a depth of 18 µm and a bottom spacing of only 1 µm, as well as a perfect gap-free coverage for micro-tubes and pyramid array. It has been proved that this 3D ITO nanowire network can be used as a transparent conductive layer for optoelectronic devices with any topography surface. Through the application on the micro-holes, -tubes and -pyramid array, some new characteristics of the 3D ITO nanowires in solar cells, sensors, micro-lasers and flexible LEDs have been found. Such 3D ITO nanowire networks could be fabricated directly on micro-irregular substrates, which will greatly promote the application of the heterotypic devices.

We design, fabricate and analyze plasmon-enhanced LEDs with the tapered Ag structure that significantly increases plasmonic coupling efficiency at a coupling distance far beyond the penetration depth. The electroluminescence intensity showed a 16-fold increase compared with planar LEDs with a coupling distance of 100 nm. The enhanced coupling efficiency with large distance is originated from the accumulated SP energy at the metal conical tip and the missing momentum provided by the corrugated surface. Therefore, the SP-enhanced LED with tapered Ag structure can maintain a high luminous efficiency and a stable working state even with thick p-GaN layer, which also guarantees a high electrical performance. Our study paves the way for a practical implementation of SP-enhanced LEDs with excellent optical and electrical properties.