Newfangled progressions in the charge transport layers impacting the stability and efficiency of perovskite solar cells

Organic-inorganic lead halide perovskite solar cells have rapidly emerged as a newfangled material for solar energy harnessing. Perovskite solar cells have succeeded in gaining a power conversion efficiency of 25% in the last year, further enhancement in the efficiency is anticipated due to advanced engineering of the different components making up the complete cell architecture with enhanced performance, stability and efficiency. Significant components of perovskite solar cell configurational architecture are the electron transport layer, active perovskite absorber layer, hole transport layer and counter electrode. Considering the profound role of transport layers in charge mobility, current review has particularly elucidated the advancements in the charge transport layers. The time duration of the review is from 2010 to 2021. However, the special focus has been laid on the recent articles. The influence of different organic and inorganic materials used for development of transport layers influencing the cell performance have been summarized. Materials used for transport layers have been modified by utilization of myriad of engineered substances through doping and surface functionalization strategies but every method have been marked by posing serious challenges towards the stability and efficiency of the cell and thus, hindering its commercialization. The review also provides an elucidation of the mechanical challenges and abatement strategies. These strategies are associated with the charge transport layers for enhancement of cell functionality.