2000 PPI silicon-based AlGaInP red micro-LED arrays fabricated via wafer bonding and epilayer lift-off
Yongzhou Zhao, Jingqiu Liang, Qinghui Zeng, Yang Li, Panyuan Li, Kaili Fan, Wenchao Sun, Jinguang Lv, Yuxin Qin, Qiang Wang, Tao Jin, Weibiao Wang
Abstract
In this article, 2000 PPI red silicon-based AlGaInP micro-LED arrays were fabricated and investigated. The AlGaInP epilayer was transferred onto the silicon substrate via the In-Ag bonding technique and an epilayer lift-off process. The silicon substrate with a high thermal conductivity could provide satisfactory heat dissipation, leading to micro-LED arrays that had a stable emission spectrum with increasing current density from 20 to 420 A/cm 2 along with a red-shift of the peak position from 624.69 to 627.12 nm ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi mathvariant="normal">Δ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>λ</mml:mi> </mml:mrow> </mml:mrow> </mml:math> = 2.43 nm). Additionally, increasing the injection current density had little effect on the CIE (x, y) of the micro-LED arrays. Further, the I-V characteristics and light output power of micro-LED arrays with different pixel sizes demonstrated that the AlGaInP red micro-LED array on a silicon substrate had excellent electrical stability and optical output.