pi-Extended porphyrin-phthalocyanine heterojunction devices (ACS Sensors 2024)

High sensitivity to NH3 with a remarkable light effect

Herein, a cross-conjugated (Ace-PQ-Ni) and a linear-conjugated (AM6) porphyrins are used to build double layer heterojunction devices by combining with lutetium bisphthalocyanine complex (LuPc2). The heterojunction effect at the porphyrin-phthalocyanine interface plays a key role in their charge transport properties. Both devices exhibit exceptionally high ammonia sensitivity at room temperature and under ambient relative humidity, with a limit of detection as good as 156 and 115 ppb for Ace-PQ-Ni/LuPc2 and AM6/LuPc2 sensors, respectively. Interestingly, AM6/LuPc2 sensors display a remarkably enhanced current variation under NH3 (x13) and a LOD as good as 83 ppb. The strikingly difference in sensing properties between the sensors upon illumination is attributed to their different p-conjugation pathways (cross-conjugation versus linear-conjugation). This work by M. Bouvet et al. results from a collaboration between ICMUB and University of North Texas (Prof. Hong Wang)

More details in ACS Sensors - 2024 click here