Owing to ecological concerns and the rapid increase in fossil fuel consumption, sustainable and efficient generation technologies are being developed. The present work aimed at manufacturing DSSC that is based on natural elements for converting the sun energy into electrical energy. ZnO nano materials are used in solar cells as binary compound semiconductor according to their stability, better conductivity, excellent mobility, the best affinity of electrons, and lower cost compared to other semiconductors. Recently, nanocellulose has shown potential as an advanced nanomaterial used in electrochemical conversion devices since it is considered the best abundant Earth biopolymer and is inexpensive and versatile. The constructed DSSC composed of plant nanocellulose (PNC) extracted from banana peel and nano-chlorophyll dye extracted from aloe vera were evaluated as the electrolyte and sensitiser, respectively. With increasing PNC content from 0 to 32 wt.%, both PV parameters and lifetime increase, and voltage decay decreases. The nano particles size modification for three materials carried by ultrasonic waves. Increasing the ultrasonic wave exposure time reduced the size of the Chl particles. The addition of PNC from banana peel to DSSC electrolyte is shown effective. The effect of varying the PNC/nano-chlorophyll content (0–32 wt.%) on the photovoltaic parameters of the DSSC was investigated. The addition of PNC significantly increased the fill factor and sunlight conversion efficiency. The DSSCs showed acceptable performance under relatively low irradiation conditions and different light intensities, indicating that they are suitable for outdoor applications.