Blue-Light-Emitting Ambipolar Field-Effect Transistors Using an Organic Single Crystal of 1,4-Bis(4-methylstyryl)benzene

An ambipolar light-emitting organic field-effect transistor (LE-OFET) based on a 1,4-Bis(4-methylstyryl)benzene (BSB-Me) single crystal was developed. The BSB-Me single crystal has very high photoluminescence quantum efficiency (Φ PL ) of 89±2%, while Φ PL of the BSB-Me vapor-deposited film is limited to a much lower value of 54±2%. Ambipolar operation with successive blue electroluminescence from the FETs based on the BSB-Me single crystals was demonstrated by realizing nearly equal electron and hole mobilities [about 0.005 cm 2 /(V s)] with asymmetric gold–calcium contacts. Since BSB-Me single crystals can perform light amplification, the BSB-Me-based ambipolar LE-OFET is a promising candidate for future electrically driven organic blue-emitting solid-state lasers.