Thin film encapsulation for quantum dot light-emitting diodes using a-SiNx:H/SiOxNy/hybrid SiOx barriers

A facile thin film encapsulation (TFE) method having a triple-layered structure of a-SiNx:H/SiOxNy/hybrid SiOx (ASH) on QD-LEDs was performed utilizing both reproducible plasma-enhanced chemical vapor deposition (PECVD) and simple dip-coating processes without adopting atomic layer deposition (ALD). The ASH films fabricated on a polyethylene terephthalate (PET) substrate show a high average transmittance of 88.80% in the spectral range of 400-700 nm and a water vapor transmission rate (WVTR) value of 7.3 x 10(-4) g per m(2) per day. The measured time to reach 50% of the initial luminance (T-50) at initial luminance values of 500, 1000, and 2000 cd m(-2) was 711.6, 287.7, and 78.6 h, respectively, and the extrapolated T-50 at 100 cd m(-2) is estimated to be approximately 9804 h, which is comparable to that of the 12 112 h for glass lid-encapsulated QD-LEDs. This result demonstrates that TFE with the ASH films has the potential to overcome the conventional drawbacks of glass lid encapsulation.

Automated summary

A triple-layered structure of a-SiNx:H/SiOxNy/hybrid SiOx (ASH) thin film encapsulation (TFE) method was performed on QD-LEDs using reproducible PECVD and dip-coating processes. The ASH films exhibited high transmittance and low water vapor transmission rate. The ASH films also demonstrated comparable performance to glass lid encapsulation in extending the lifetime of QD-LEDs.