Beryllium‐Assisted p‐Type Doping for ZnO Homojunction Light‐Emitting Devices

Abstract

A key step in realization of a ZnO homojunction light-emitting diode is the effective p-type doping in ZnO:N. In this article, a feasible route is demonstrated to enhance hole doping in ZnO:N fi lms by the assistance of Beryllium. The newly synthesized p-type ZnO is applied in light-emitting devices. The corresponding p-i-n junction exhibits excellent diode characteristics, and strong near band edge ultraviolet emissions is also observed even at temperatures as high as 400 K under the injection of continuous current. The results represent a critical advance toward the development of high-effi ciency and stabilized p-type ZnO, which is also a desirable key step for future ZnO-based optoelectronic applications.

Experimental Evidence on Stability of N Substitution for O in ZnO Lattice

“…31 From highresolution X-ray diffraction (HRXRD), the narrow full width at half-maximum (fwhm) of the rocking curves, the 51 arcsec of (002) and 36 arcsec of (102) shown in Figure 3a further indicate the crystallinity of ZnO:N film with an ultralow dislocation density. The fwhm values are much lower than the previously reported values of ZnO:N and Be-doped ZnO:N films (both >850 arcsec) grown on sapphire, 12 and are close to the best values of the reported homoepitaxial ZnO:N films ((002) of 49 arcsec, (100) of 38 arcsec). 32 Using the known methods, 31,33 the screw and the edge dislocation densities of the ZnO:N films are estimated to be about 5.18 × 10 6 cm −2 and 5.65 × 10 5 cm −2 , respectively.…”

Design Principles of p-Type Transparent Conductive Materials

“…The same effect occurs to ZnBeO alloy. Considering that the Be−N bond is stronger than Zn−N bond, Chen et al 73 thought that introducing a small fraction of Be might stabilize more N atoms in ZnO, leading to the enhancement of p-type conductivity. So they constructed a UV p-i-n junction LEDs based on p-type BeZnO:N, and the transition level of Be-assisted N O is lowered to 0.121 eV as expected, indicating that the incorporation of Be can indeed improve the p-type doping performance.…”

Controllable Carrier Type in Boron Phosphide Nanowires Toward Homostructural Optoelectronic Devices

“…More importantly, if two dissimilar types of semiconductor materials were employed, electrons and holes will be severely scattered in heterostructures arising from the grain boundary at the alloy interface between two semiconductors; this will inevitably lead to a performance depreciation of those smart devices . To this end, researchers propose that the homojunction is established on the interface between layers of similar semiconductor materials. , The only requirement in contrast to a heterojunction is that the same semiconductor (same band gap but typically have different doping) is found on both sides of the junction …”

“…11 To this end, researchers propose that the homojunction is established on the interface between layers of similar semiconductor materials. 12,13 The only requirement in contrast to a heterojunction is that the same semiconductor (same band gap but typically have different doping) is found on both sides of the junction. 14 The materials suitable for the homojunction so far are limited.…”