Description
1,4,5,8-Naphthalenetetracarboxylic dianhydride (NTCDA) has a naphthalene core with four carboxylic acids at the 1, 4, 5, and 8 positions, with each adjacent carboxylic acid forming an anhydride. NTCDA is aromatic, stable, planar, and highly symmetric chemically, and also possesses favourable electrical properties. Due to the electron-deficient nature of the carboxyl group, NTCDA is known to be a strong electron acceptor molecule with an electron affinity as high as 4.0 eV. It has been demonstrated that NTCDA significantly improves the electrical conductivity of co-deposited thin films of NTCDA and a wide range of metals including indium, magnesium and aluminium. The high electron conductivity of co-deposited NTCDA/In films also strongly suggests that co-deposited NTCDA/In films are excellent electron transport layers for organic light emitting diodes and photovoltaic devices.