Study of GaN/InGaN Light-Emitting Diodes with Specific Zirconium Oxide (ZrO2) Layers

An interesting device design including a zirconium oxide (ZrO 2 ) current blocking layer (CBL) and a ZrO 2 surface passivation layer (SPL) is employed to manufacture a GaN/InGaN light-emitting diode (LED). Based on the inherently good performance of ZrO 2 , the current spreading effect and the undesired surface leakage are efficiently enhanced and suppressed, respectively. Energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are used to study the relevant properties. It is found that by series calibration, 50 nm is the proper thickness of the ZrO 2 CBL and SPL. The peak emission wavelength of the proposed LEDs is around 452 nm. Experimentally, at the operating condition of 110 A cm −2 , the proposed Device L3 with a 50 nm-thick ZrO 2 CBL and a 50 nm-thick ZrO 2 SPL demonstrates improvements of 66.1% in light output power (LOP) and 64.5% in wall plug efficiency (WPE) as compared to a traditional Device L1 without the specific design. Furthermore, the proposed Device L3 presents a notable enhancement in the light emission mapping image in comparison to the traditional LED. So, the proposed device design which incorporates a proper ZrO 2 CBL and ZrO 2 SPL, is beneficial for manufacturing GaN/InGaN LEDs.