Composition and Bandgap‐Graded Semiconductor Alloy Nanowires

Abstract Semiconductor alloy nanowires with spatially graded compositions (and bandgaps) provide a new material platform for many new multifunctional optoelectronic devices, such as broadly tunable lasers, multispectral photodetectors, broad‐band light emitting diodes (LEDs) and high‐efficiency solar cells. In this review, we will summarize the recent progress on composition graded semiconductor alloy nanowires with bandgaps graded in a wide range. Depending on different growth methods and material systems, two typical nanowire composition grading approaches will be presented in detail, including composition graded alloy nanowires along a single substrate and those along single nanowires. Furthermore, selected examples of applications of these composition graded semiconductor nanowires will be presented and discussed, including tunable nanolasers, multi‐terminal on‐nanowire photodetectors, full‐spectrum solar cells, and white‐light LEDs. Finally, we will make some concluding remarks with future perspectives including opportunities and challenges in this research area.