Optical and Thermal Performances of (Ga,In)N/GaN Light Emitting Diodes Transferred on a Flexible Tape

Blue (Ga,In)N-based light-emitting diodes (LEDs) grown on a Si(111) substrate by metal-organic vapor phase epitaxy are transferred on a flexible tape after the Si substrate removal. Their optical and thermal behaviors are measured and compared to those of regular LEDs on Si. The light output power of the flexible LEDs is increased due to a higher light extraction efficiency related to the removal of the absorbing Si substrate. However, the maximum output power is limited by thermal effects due to the lower thermal conductivity of the flexible tape. Monitoring the electroluminescence wavelength of the flexible LEDs allows determining their acceptable operating range. The maximum flexible LED luminance is 5×10 5 cd/m 2 .