Abstract
In this research, we demonstrated a novel planar-type InP-based near-infrared (NIR) broadband light-emitting diodes (LED) by using the rapid thermal diffusion (RTD) technique. The active layer consists of multiple double hetrostructures (DH) of InP/GaxIn1-xAsyP1-y layers and target to emit a broadband spectrum of 1-1.7 μm at once. In addition, we employed In0.52¬Al0.48As as electron blocking layer to improve the extraction efficiency. Moreover, when y=2.2x, GaxIn1-xAsyP1-y and In0.52¬Al0.48As are both lattice-matched to InP substrate. The p-type region were formed by RTD process with the zinc-phosphorous-dopant-coating (ZPDC) as the spin-on dopant (SOD) source to avoid high leakage from mesa-type structure. A gallium-doped zinc oxide (GZO) thin-film was adopted as transparent conductive layer to increase the light emitting region of LEDs. Ultimately, we have successfully fabricated a small series resistance Rs of 6.5-8 Ω, and ultra-small leakage current of 0.465-95 nA under 5 V reverse bias. Moreover, the full-width of half-maximum (FWHM) is up to 563 nm and has an extraordinary total light output power of 5.8 mW.