Shape memory polymer solar cells with active deformation

The reliable and lightweight deployable solar arrays require the capability of large deformation for packaging and the ability to actively deform for deployment. To satisfy such demands, the shape memory polymer solar cells (SMPSCs) are fabricated and demonstrated in this paper by using flexible and conductive silver nanowire/shape memory copolyamide (AgNW/SMPI) composite film as the transparent substrates. The AgNW/SMPI composite film has good optical transparency (~73% at the wavelength of 450 ~ 1100 nm), smooth surfaces (average RMS: ~3.32 nm), good shape memory performances (shape fixation ratio > 98%, shape recovery ratio > 98%), and can maintain excellent conductivity (~10Ω/□) after mechanical deformations with large strain. Owing to the shape memory effect of the substrate, SMPSCs can be deformed into arbitrary shape and actively recover to the original shape upon heating. The power conversion efficiency of SMPSC (2.94%) is lower than that of ITO-based solar cells with the same structure (3.44%), due to the relatively lower optical transparency of SMPI. However, SMPSCs can maintain good photovoltaic performances after 50 bending-recovery cycles or few shape recovery cycles, demonstrating better flexibility and durability than ITO-based solar cells. The SMPSCs have the potential to be used in deployable solar arrays, and the transparent conductive SMPI film electrodes have the potential to be used in areas of sensors, medical probes, and displays.