Perovskite　solar　cells　(PSCs)　are　set　to　be　game　changing　components　in　next-generation　photovoltaic　technology　due　to　their　high　efficiency　and　low　cost.　In　this　article,　recent　progress　in　the　development　of　perovskite　layers,　which　are　the　basis　of　PSCs,　is　reviewed.　Achievements　in　the　fabrication　of　high-quality　perovskite　films　by　various　methods　and　techniques　are　introduced.　The　reported　works　demonstrate　that　the　power　conversion　efficiency　of　the　perovskite　layers　depends　largely　on　their　morphology　and　the　crystalline　quality.　Furthermore,　recent　achievements　concerning　the　scalability　of　perovskite　films　are　presented.　These　developments　aim　at　manufacturing　large-scale　perovskite　solar　modules　at　high　speed.　Moreover,　it　is　shown　that　the　development　of　low-dimensional　perovskites　plays　an　important　role　in　improving　the　long-term　ambient　stability　of　PSCs.　Finally,　these　latest　advancements　can　enhance　the　competitiveness　of　PSCs　in　photovoltaics,　paving　the　way　for　their　commercialization.　In　the　closing　section　of　this　review,　some　future　critical　challenges　are　outlined,　and　the　prospect　of　commercialization　of　PSCs　is　presented.