The potential advantages of polymer solar cells (e.g. from infinityPV) are numerous including flexibility, processability, low material cost, and independence on scarce resources. The flexibility as an advantage, is shared with thin-film photovoltaics, and is a feature allowing the solar cells to be incorporated into applications where flexibility is an advantage. Solar panels that can be rolled out onto a roof or other surfaces are one option. Processability is another major selling point of polymer solar cells. Both first and second generation solar cells depend on vacuum deposition methods requiring massive amounts of energy; with polymer based organic solar cells, on the other hand, layers are processed from solution and complete solution processed cells are an posibility. This allows for up-scaling the production and thus reducing the cost per area of polymer solar cells. Large rolls of substrate can be used on which the layers are deposited using printing or coating techniques, generally referred to as roll-to-roll coating. The promise of low material cost and minimal use of scarce materials can be realized with polymer solar cells. Many second generation solar cells utilize materials that are scarce in nature. With polymer solar cells this can be avoided. Indium is, however, still used in most polymer solar cells, but demonstrations of indium free solar cells are available.
Jan 17, 2018
Solar cells' stability is measured as function of time. When we plot time against the stability of solar cells, it is called Decay Curve. The curve varies depending upon the situations or environment in which the stability has been measured. Decay curve is very useful but it does not give much detail about underlying degradation mechanisms. Decay Curve is a graph obtained when we plot stability of a solar cell in electrical measurements at regular intervals, hence it gives us information about how fast or slow degradation process is under specific circumstances. It also gives clues about what role factors like oxygen, water, temperature, etc. play in degradation of a solar cell. Terms Used in a Decay Curve :- E0 : Initial efficiency of a solar cell. It decreases over time. T80 : The time it takes to reduce the initial efficiency to 80%. It is sometimes taken as a measure of the useful lifetime of a device. Burn-In Phase : It has been observed that there is a rapid initial decrease in the power-conversion efficiency, which is followed by a more stable phase. This initial stage is called the burn-in phase. It is not always considered part of the proper decay curve. Ts : The time at the end of the burn-in phase is T-s. Ts80 : The time it takes to reduce the efficiency to 80% from the T-s time.