[19a-P5-1~38] 12.5 Organic solar cells

▼ [19a-P5-11] Surface potential mapping in terraced bilayer perylene derivative and phthalocyanine: A study about charge redistribution in p-n domain interfaces

〇(D)ahmad bin Mohdfairus¹, Tomokazu Iyoda¹, Toshiyuki Abe², Keiji Nagai¹ (1.Integ. Mol. Eng. Div., Chem. Res. Lab., Tokyo Tech., 2.Dept. of Frontier Mater. Chem., Hirosaki Univ.)

Keywords:organic semiconductor,kelvin probe,heterojunction

In this work, phthalocyanine (H₂Pc) and 3,4,9,10-perylenetetracarboxylic-bis-benzimidazole (PTCBI) based terraced bilayer systems were prepared as a large-scale (ca. 1cm x 1cm) thin film heterojunction model to study surface potential of boundary as p-type and n-type material formed interfacing structure (p-n domain interfaces). As the scanning made between bilayer region and single layer region, the boundary region in the terraced bilayer ITO/PTCBI(40 nm)/H₂Pc(40 nm) was observed to have lateral surface potential rise, while for terraced bilayer ITO/H₂Pc(40 nm)/PTCBI(40 nm) showed a transition of low potential and high potential within the lateral region. At the boundary region of terraced bilayer ITO/PTCBI/H₂Pc, observation showed that surface potential was distributed (440 -540 mV) into lateral region to be more than 30 μm width. Moreover, lateral surface potential rise was observed to be ca. 80 – 110 mV which is higher than that of the bilayer region. The observations of those two distinct characteristics of build-up and non build-up lateral surface potential are discussed based on a charge redistribution mechanism in the boundary region.