Soldering of solution-processed organic vertical transistor and light-emitting diode on separate glass substrates by tin micro-balls

Abstract

The vertical organic space-charge-limited transistor made of P3HT and small-molecule phosphorescent organic light-emitting diode (OLED) are made on two separate glass substrate by blade coating, then soldered vertically together by tin balls with 40 mu m diameter. The soldering is done by hot wind of 150 degrees C for 5 min Contact resistance is only 10 Omega. The vertical transistor is annealed at 150 degrees C for 5 min before soldering to enhance the output current up to 25 mA/cm(2) and give high thermal stability. Both OLED and the annealed vertical transistor are not affected by the soldering process. The vertical transistor has 1/4 of the OLED area and turns on the bottom-emission white OLED up to 300 cd/m(2) and orange OLED up to 600 cd/m(2). The entire operation is within 8 V. OLED and transistor array can therefore be made on separate glass substrates then soldered together to form the display. (C) 2013 Elsevier B. V. All rights reserved.