CNT sensor arrays with P-I-N diodes

A novel active matrix array approach suitable for a compact multi-channel gas sensor platform is presented. Each sensor site utilizes carbon nanotubes (CNT) on top of a pair of interdigitated electrodes (IDEs) as the gas sensing element. The proposed active matrix sensor array utilizes an array of P-I-N diodes each connected in series with an IDE. The use of P-I-N diodes enables row and column addressing of each sensor thus significantly reducing the required wiring compared to individually addressed sensors. In this work, P-I-N diodes were implemented using either silicon-on insulator (SOI) or Low Temperature Poly-Silicon (LTPS) thin film technology thus validating that both wafer and glass based approaches can be used for the mass manufacture of proposed multi-channel sensor platforms. The functionality of 8×8 and 16×16 sensor arrays is proven with the help of a PEDOT:PSS cover. Data are also presented for the 8×8 arrays and the detection of ammonia (NH3) and chlorine (Cl2) vapor sources is demonstrated.