Low-Temperature Annealed Perovskite Solar Cell Via Solvent Engineering

Perovskite solar cells(PSCs)are gaining attention day by day due to their ease of production,low material cost and ideal opto-clectronic properties.Perovskite boosting power conversion efficiency up to 22%in recent times is evident to its importance as an emerging contender in the field of photovoltaic.Its rise in scientific field of energy conversion material could be ascribed to recent advancement in compositional engineering,solvent engineering,stoichiometric alignment and novel fabrication methods.Despite such level of augmentation in power conversion efficiency of perovskite solar cell in recent times.It is still hard to fabricate a commercially feasible perovskite film due to its lengthy annealing time at elevated temperature,which is a also a bottleneck along with stability issue for a commercial perovskite solar cell.Herein,I introduced a solvent engineering assisted low-temperature annealing technique for peovskite films.Ternary solvent system based on N-methyl-2-pyrrolidone(NMP).dimethylacetamide(DMAC)and dimethylsulfoxide(DMSO)are mixed in the precursor solution to produce quality perovskite films by annealing at 50? for 30 minutes.Solvents affinity towards non-polar anti-solvent and their coordination strength to form intermediate phase is exploited by adjusting respective volume potions.NMP and DMAC are known for their affinity towards non-polar anti-solvent.while DMSO resilient nature makes it able to produce stable adduct.NMP and DMAC are used as principal and co-solvent in the perovskite precursor solution,where as DMSO is added as an solvent additive,instead of co-solvent as traditionally happens.It was observed that 10%of DMSO in mixed solvent precursor solution produces a uniform,pin-hole free and compact peovskite layer.The potent film exhibits strong absorption spectrum with reduced trap states and enhanced spectral response.Best device performance from the prepared devices show a highest efficiency of 18.19%.which was quite competative with the efficiency of 18.58%achieved by traditionally high-temperature annealing.The prepared devices also displayed a resilient nature of stable behaviour by retaining more than 85%of initial efficiency when kept in ambient environment of 40%humiclit)for two weeks.These novel outcomes may offer a way to fabricate low-temperature annealed,high-quality perovskite layers and consequently simplify the manufacture of efficient and cost-effective devices.