Study Of Physically Transient Insulating Material As A Potential Platform For Flexible Organic Solar Cell

As an emerging technology, the key feature of the transient electronic technology is that it can be partially or completely controlled disappeared at the given time after the completion of the target task. With the development of nano thin film, the transient electronic technology has great potential. It not only has great potential in biomedical applications, such as artificial joints and absorbable surgical suture, etc., but also in national defense construction and national security, such as degradable power equipment, information storage systems, information detection system, etc..The traditional electronic information materials are not fully suitable for the transient electronic devices. Presently, the material system suitable for the transient electronic devices is not to make it clear. Therefore, dissolvable polyvinyl alcohol is used as the basic material in this paper from the point of view of controllable physical transient material. The optically physical properties, mechanical properties and controllable degradation properties are studied by adding gelatin or sucrose. Futher more, the prospect of using this kind of composite thin film as a transient substrate in organic solar cell is preliminarily explored. Specific conclusions are as follows:Firstly, polyvinyl alcohol is a kind of material with flexibility and small elastic modulus. Adding different quality of gelatin, PVA/gelatin composites have rapid increase in elastic modulus, hardness. However, increasing the amount of gelatin, the elastic modulus decreases, it is due to the continuous phase of gelatin. The addition of gelatin also makes the decomposition temperature of the composites increased and the temperature resistance rised, the main reason is PVA and gelatin molecules have a strong interaction. Because of the occurrence of esterification, ester groups are formed. On the section of dissolution, the composites films are decreased with the addition of gelatin. In addition, with the increase of the amount of gelatin, the dissolution of the composites decreased. In order to realize the material's controllability, the 63.2% dissolution is defined as transient threshold, corresponding time points are defined as time constant. In this case, the transient characteristic of PVA/gelatin is poor, and the time constant is a large value.Secondly, adding sucrose into PVA, PVA /sucrose composite has small values of the elastic modulus. With the increase of sugar content, the elastic modulus decreased. It indicates that the flexibility of PVA/sucrose composites are good. For the transmittance, PVA/sucrose composites film transmittance of up to 90%, and PVA/sucrose composites thin films at high dissolution and fast dissolution rate. With the increase of the amount of sucrose, the dissolution of the composites decreased. Generally speaking, PVA/sucrose composites film has good transient characteristic, and has a small value of time constant.Thirdly,different proportion of PVA/gelatin and PVA/sucrose are used as the substrate of the organic solar cell. The structure is: PVA based/Ag/ MoO₃/P3HT : PCBM/Ca/Ag, the power conversion efficiency of the battery is 1.88, and the filling factor is 57%, the best performance of the battery substrate material is the highest quantity of sucrose. After addition of gelatin, the performance of the device is reduced. The best transient characteristics of the battery device suggest that the substrate is a PVA/sucrose composite, which has been broken in the middle of a few seconds. On the contrary, the dissolution rate of PVA/gelatin is slower, and the substrate film is still intact finally. All of devices are eventually failed. This conclusion is consistent with the results obtined by the dissolution of the composites film.