Resonant cavity effect optimization of III-nitride thin-film flip-chip light-emitting diodes with microsphere arrays.

Comprehensive studies were carried out to investigate the light extraction efficiency of thin-film flip-chip (TFFC) light-emitting diodes (LEDs) with anatase TiO(2) microsphere arrays by employing the finite-difference time-domain method. The quantum well position and the resonant cavity effect were studied to obtain optimum light extraction for the planar TFFC LED. Further enhancement in light extraction was achieved by depositing microsphere arrays on the TFFC LED. The calculation results showed that the sphere diameter, packing density, and packing configuration have significant effects on the light extraction efficiency. A maximum light extraction efficiency of 75% in TFFC LEDs with microsphere arrays has been achieved. This study demonstrates the importance of optimizing the quantum well position, cavity thickness, sphere diameter, sphere packing density, and packing configuration for enhancing the light extraction efficiency of TFFC LEDs with microsphere arrays.