Figure 1: InGaN MQW nanowire structures.
From: Multi-quantum-well nanowire heterostructures for wavelength-controlled lasers
a, Schematic diagram of an MQW nanowire and magnified cross-sectional view of a nanowire facet highlighting InGaN/GaN MQW structure. The InGaN layer is indicated in yellow colour. b, Low-resolution TEM image of an MQW nanowire structure. The scale bar is 500 nm. c, High-resolution TEM image of an MQW nanowire structure taken along the [0001] zone axis. The white arrow indicates the 
direction (along the nanowire axis). The scale bar is 5 nm. Inset: Corresponding electron diffraction pattern indexed for the [0001] zone axis. d, Dark-field cross-sectional STEM image recorded along the 
zone axis of a 26MQW nanowire structure. Dashed lines indicate core/shell interface. The scale bar is 100 nm. Inset: Corresponding electron diffraction pattern indexed for the 
zone axis. e, Left: Schematic GaN wurtzite crystal structure viewed along the 
direction. Right: Simulated and experimental CBED patterns along the 
zone axis from a 216-nm-thick MQW nanowire cross-sectional sample. f–h, Dark-field cross-sectional STEM images recorded along the 
direction at the 
facet of 3MQW (f), 13MQW (g) and 26MQW (h) nanowire structures; scale bars are 20, 50, and 20 nm, respectively.
