An unprecedentedly stable CH3NH3PbI3 film synthesized by a modified chemical vapor transport method is demonstrated. The results show that the crystal structure, light absorption, and device efficiency do not degrade after storing for 100 d in air with 40% relative humidity, while the conventional solution-processed perovskites are usually stable for less than 20 d in similar conditions.

The responses of individual odour sensors combined into an array, where each sensor possesses slightly different response selectivity and sensitivity towards the sample odours, when combined by suitable mathematical methods, can provide information to discriminate between many sample odours (Pearce et al., 2002). Arrays of gas and odour sensors, made using different technologies, are finding th...