Solution-Processed Chloroaluminum Phthalocyanine (ClAlPc) Ammonia Gas Sensor with Vertical Organic Porous Diodes.

Govindsamy Madhaiyan,An-Ting Sun,Sheng-Fu Horng,Hsiao-Wen Zan,Hsiao-Wen Hung,Li-Yin Chen,Hsin-Fei Meng

doi:10.3390/s21175783

Abstract

In this research work, the gas sensing properties of halogenated chloroaluminum phthalocyanine (ClAlPc) thin films were studied at room temperature. We fabricated an air-stable ClAlPc gas sensor based on a vertical organic diode (VOD) with a porous top electrode by the solution process method. The surface morphology of the solution-processed ClAlPc thin film was examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The proposed ClAlPc-based VOD sensor can detect ammonia (NH3) gas at the ppb level (100~1000 ppb) at room temperature. Additionally, the ClAlPc sensor was highly selective towards NH3 gas compared to other interfering gases (NO2, ACE, NO, H2S, and CO). In addition, the device lifetime was tested by storing the device at ambient conditions. The effect of relative humidity (RH) on the ClAlPc NH3 gas sensor was also explored. The aim of this study is to extend these findings on halogenated phthalocyanine-based materials to practical electronic nose applications in the future.

Highlights

In recent years, the electronic nose (e-nose) has received considerable attention due to its potential applications in several fields including environmental monitoring, food storage, healthcare, industry, automobiles, military, and cosmetics [1,2,3,4,5]
The surface morphology of the solution-processed ClAlPc thin film was investigated with the aid of a field emission scanning electron microscope (SEM SU8010) and an atomic force microscope (Bruker Edge)
Even the ClAlPc sensor stored for 30 days exhibits a stable response in repeated test cycles. These results suggest that the proposed ClAlPc sensor exhibits good selectivity as well as repeatability

Summary

Introduction

The electronic nose (e-nose) has received considerable attention due to its potential applications in several fields including environmental monitoring, food storage, healthcare, industry, automobiles, military, and cosmetics [1,2,3,4,5]. For an e-nose system, the choice of reliable gas sensors is the key factor for integration Based on their working principle, different types of gas sensors have been demonstrated for their related applications [6,7]. Acoustic, electrochemical, and catalytic sensors have shown some limitations such as a high cost, huge size, heavy weight, low reproducibility, poor selectivity, and complex system. In this context, solid-state gas sensors are appropriate candidates for developing a compact e-nose technology due to their low production cost, easy handling, good sensing behavior, and device miniaturization [5]

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Conclusion