Quantitative analysis of leakage current in III-nitride micro-light-emitting diodes
Abstract
The electrical characteristics under forward- and reverse-bias conditions of III-nitride blue and green micro-light-emitting diodes (μLEDs) are analyzed. A fitting model is proposed to determine the contributions of reverse leakage current and the effectiveness of sidewall treatments. Moreover, the forward-bias currents of the μLEDs are examined using the extracted ideality factor to examine the impacts of sidewall defects. The results show that sidewall treatments are highly effective for suppression of leakage currents. From the efficiency perspective, higher wall-plug efficiency (WPE) than external quantum efficiency (EQE) is observed when the operating voltage is lower than the photon voltage in both blue and green 20 × 20 μm2 devices. This enhancement of the WPE over the EQE is due to the suppression of Shockley–Read–Hall (SRH) nonradiative recombination. These observations indicate that μLEDs with sidewall treatments not only improve optical performance but also further enhance the electrical performance of devices by suppressing the leakage current paths due to SRH nonradiative recombination processes.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (10)
Matthew S. Wong
Materials Department, University of California 2 , Santa Barbara, California 93106,
Tanay Tak
Materials Department, University of California 1 , Santa Barbara, California 93106,
Andrea Y. Ni
Department of Electrical and Computer Engineering, University of California 2 , Santa Barbara 93106, California,
Kent Nitta
Materials Department, University of California Santa Barbara 2 , Santa Barbara, California 93106,
Srinivas Gandrothula
Materials Department, University of California 1 , Santa Barbara 93106, California,
JaeKwon Kim
Seoul Viosys 3 , 97-11, Sandan-ro 163beon-gil, Danwon-gu, Ansan-si, Gyeonggi-do, 15429,
NamGoo Cha
Seoul Viosys 3 , 97-11, Sandan-ro 163beon-gil, Danwon-gu, Ansan-si, Gyeonggi-do, 15429,
Umesh K. Mishra
Department of Electrical and Computer Engineering, University of California , Santa Barbara, California 93106,
James S. Speck
Materials Department, University of California Santa Barbara 2 , Santa Barbara, California 93106,
Steven P. DenBaars
Electrical and Computer Engineering Department, University of California Santa Barbara 1 , Santa Barbara, California 93106,