Conductive Metallophthalocyanine Framework Films with High Carrier Mobility as Efficient Chemiresistors

The poor electrical conductivity of two‐dimensional (2D) crystalline frameworks greatly limits their utilization in optoelectronics and sensor technology. Herein, we describe a conductive metallophthalocyanine‐based NiPc‐CoTAA framework with cobalt(II) tetraaza[14]annulene linkages. The high conjugation across the whole network combined with densely stacked metallophthalocyanine units endows this material with high electrical conductivity, which can be greatly enhanced by doping with iodine. The NiPc‐CoTAA framework was also fabricated as thin films with different thicknesses from 100 to 1000 nm by the steam‐assisted conversion method. These films enabled the detection of low‐concentration gases and exhibited remarkable sensitivity and stability. This study indicates the enormous potential of metallophthalocyanine‐based conductive frameworks in advanced stand‐off chemical sensors and provides a general strategy through tailor‐make molecular design to develop sensitive and stable chemical sensors for the detection of low‐concentration gases. A fully π‐conjugated and conductive 2D metallophthalocyanine framework with cobalt tetraaza[14]annulene linkages (see structure) exhibited high electrical conductivity of up to 0.52 S m−1 and a high carrier mobility of 0.15 cm2 V s−1. Thin films of the material with thicknesses of 100–1000 nm functioned as efficient chemiresistors and displayed high sensitivity and selectivity towards gases at low concentrations.