Mixed host organic light-emitting devices with low driving voltage and long lifetime

Abstract

In this letter, we present and analyze the device performance of the mixed host ͑MH͒ organic light-emitting devices ͑OLEDs͒. The host of the emitting layer ͑EML͒ material in this device consists of a hole transport layer ͑HTL͒ and an electron transport layer ͑ETL͒ fabricated by coevaporation. The bipolar transport characteristic of the MH layer helps to reduce the driving voltage. Device lifetime is increased due to the elimination of the sharp boundary of the HTL/EML interface. Combining the MH structure with a high mobility electron ETL material, bis͑10-hydroxybenzo͓h͔qinolinato͒beryllium, the OLED has shown a brightness of 27 600 cd/ m 2 at a driving voltage of 5 V, and a lifetime four times longer than that of a conventional OLED.

Al2O3/ZrO2 Nanolaminates as Ultrahigh Gas‐Diffusion Barriers—A Strategy for Reliable Encapsulation of Organic Electronics

“…[1] In addition, the residual moisture in the cavity between the organic device and lid is further minimized by an opaque getter material. [4] For large-area, flexible, or transparent applications, glass-lid encapsulation is not suitable. A promising alternative is thin-film barriers of metal oxides or nitrides, such as Al 2 O 3 , SiO 2 , TiO 2 , or SiN.…”

Efficient hybrid white organic light-emitting diodes for application of triplet harvesting with simple structure

“…Hole mobility of TCTA and 4P-NPD were μ h (TCTA) : 3.0 × 10 -4 cm 2 /V s and μ h (4P-NPD) : 6.6 × 10 -4 cm 2 /V s [15,16]. For reason of similar hole mobility, we was substitute 4P-NPD with TCTA for less material and can be produced a simple hybrid WOLEDs structure.…”

Improved out-coupling efficiency of organic light emitting diodes by manipulation of optical cavity length

“…However, compared with red phosphorescent materials, green components have still many problems because it shows relatively shorter lifetime than red components. To overcome such issue, the modification of PHOLEDs by changing the composition of emitting layer (EML) through mixed host approach [5,6] and/or bipolar host approach has been broadly investigated [7,8]. In addition, the adjustment of relative current density (e.g.…”