Light-emitting diode matrix and method for producing a light-emitting diode matrix

The invention relates to a light-emitting diode matrix (100) comprising a substrate (102), a first and a second electrode (104, 106), which are configured in or on the substrate (102) and are insulated from one another, a first organic layer (108) on the first electrode (104) and a second organic layer (110) on the second electrode (106). The first organic layer (108) is separated from the second organic layer (110) by a separation device (112). The light-emitting diode matrix (100) also comprises a cover electrode (114) with a region (114a) that is situated on the first organic layer (108) and a region (114b) that is situated on the second organic layer (110). The regions (114, 114b) of the cover electrode (114) are interconnected in an electrically conductive manner by means of a region (114c) that is situated on the separation device (112)

OLED-on-CMOS integration for optoelectronic sensor applications

Highly-efficient, low-voltage organic light emitting diodes (OLEDs) are well suitable for post-processing integration onto the top metal layer of CMOS devices. This has been proven for OLED microdisplays so far. Moreover, OLEDon-CMOS technology may also be excellently suitable for various optoelectronic sensor applications by combining highly efficient emitters, use of low-cost materials and cost-effective manufacturing together with silicon-inherent photodetectors and CMOS circuitry. The use of OLEDs on CMOS substrates requires a top-emitting, low-voltage and highly efficient OLED structure. By reducing the operating voltage for the OLED below 5V, the costs for the CMOS process can be reduced, because a process without high-voltage option can be used. Red, orange, white, green and blue OLED-stacks with doped charge transport layers were prepared on different dualmetal layer CMOS test substrates without active transistor area. Afterwards, the different devices were measured and compared with respect to their performance (current, luminance, voltage, luminance dependence on viewing angle, optical outcoupling etc.). Low operating voltages of 2.4V at 100cd/m2 for the red p-i-n type phosphorescent emitting OLED stack, 2.5V at 100cd/m2 for the orange phosphorescent emitting OLED stack and 3.2V at 100cd/m2 for the white fluorescent emitting OLED have been achieved here. Therefore, those OLED stacks are suitable for use in a CMOS process even within a regular 5V process option. Moreover, the operating voltage achieved so far is expected to be reduced further when using different top electrode materials. Integrating such OLEDs on a CMOS-substrate provide a preferable choice for silicon-based optical Microsystems targeted towards optoelectronic sensor applications, as there are integrated light barriers, optocouplers, or lab-onchip devices

In-line deposition of high-efficiency p-i-n organic light-emitting devices

OLED devices with electrically doped transport layers show low operating voltage, high efficiency and long lifetime. This paper demonstrates that the concept of p- and n-type electrical doping can be applied under manufacturing conditions. It shows that handling of dopants, adjustment of doping concentrations, and preparation of p-i-n type OLED stacks is possible with the worldwide first vertical in-line set-up. An in-line-manufactured highly efficient RGB-OLED-system is presented

Influence of properties of sputtered Al cathodes on OLED characteristics

The dependence of device performance on the properties of Al cathodes of p-i-n OLEDs (Organic Light Emitting Diode) is investigated in this study. OLEDs were fabricated in vertical in-line equipment, and organic materials were evaporated in vacuum on ITO substrates. The OLED stack comprised doped charge transport layers at both electrode sides and an orange-red emitting layer consisting of alpha-NPD(4,4-bis [N-(1-naphtyl)-N-phenylamino]biphenyl) and Iridium(III)bis(2-methyldibenzo-[f,h]quinoxaline)(acetylacetonate) as host and phosphorescence dye dopant, respectively. In order to form the cathode on organic layers DC magnetron sputtering has been applied and the sputter process parameters were varied. For comparison an OLED with evaporated Al cathode was prepared as well. The fabricated OLEDs were characterized by I-V-L measurements. Differences in operating voltages as well as in luminescent efficiencies were observed. Investigations on electrical, optical and morphological properties of Al films on organic layer were performed to explain the origin of the different characteristics of OLEDs. The properties of the Al cathode films affect carrier injection into organic layer as well as optical out-coupling and cause therefore differences in external efficiencies of OLEDs

In-line deposition of high-efficiency p-i-n organic light-emitting devices

OLED devices with electrically doped transport layers show low operating voltage, high efficiency and long lifetime. This paper demonstrates that the concept of p- and n-type electrical doping can be applied under manufacturing conditions. It shows that handling of dopants, adjustment of doping concentrations, and preparation of p-i-n type OLED stacks is possible with the worldwide first vertical in-line set-up. An in-line-manufactured highly efficient RGB-OLED-system is presented