Matrix‐Free Quantum Dot‐Deposited Films with Perfect Color Conversion for Automotive Taillights

Abstract Automotive taillights play crucial roles in providing essential signals about vehicle status, representing brand design identity, and contributing to aesthetic appeal. In this study, a host matrix‐free quantum dot (QD)‐deposited films for automotive taillight applications is developed using the aerosol‐assisted deposition (AAD) method. Direct deposition of thin high‐density red‐emitting QD (RQD) layers (≈4.3 µm thick) onto blue mini‐light‐emitting diodes (LEDs) (mini‐BLEDs) as light sources resulted in complete wavelength conversion with no blue light leakage. This approach addresses the limitations of conventional inorganic‐phosphor‐based LEDs by achieving high color purity, uniform surface emission, and enhanced luminous efficiency. RQD‐deposited films embedded with spherical silica particles as scattering agents demonstrated a luminous efficiency of 32.9 lm W⁻¹. The AAD method enabled large‐area patterned deposition with exceptional uniformity, as confirmed by color coordinate variations of less than 0.003 across a 10 cm × 10 cm film. A fabricated taillight prototype exhibited vivid red emission and high visibility. These findings demonstrate the potential of the QD‐BLED technology as a next‐generation lighting solution for automotive applications, offering a balance between technical performance and design flexibility.