Journal Article B←N bond CsPbI3 NIR absorption all-polymer solar cell all-polymer solar cells backbone ordering core engineering device performance electron-deficient unit fused-ring electron acceptor fused-ring electron acceptors graphene/high-index Cu substrates high density high ordering hybrid materials image sensors isomeric end groups large scale film growth macromolecular films molecular packing morphology nonfullerene nonfullerene acceptors organic photovoltaics organic solar cells patterned potentials perovskite nanowires perovskite quantum dots polymer acceptor