An algal-alginate film to be utilized in a Bio-photovoltaic device to generate bioelectricity.The algal-alginate film includes algal cells and a glass substrate with a semi-conducting or conducting layer. The algal cells are immobilized by utilizing sodium alginate, and adding sodium alginate powder into sterile distilled water and continuously stirred for a predefined time duration. The algal cells are harvested by centrifugation process in a logarithmic growth phase at 2000 RPM for 10 minutes and suspended in BBM to form a concentrated algal alginate suspension. The algal alginate suspension is spread over the semi-conducting or conducting layer. Then Sterile CaCl2 sprayed on the algal alginate suspension surface to accomplish gelation process between 60 minutes and 80 minutes to form a 2-millimeter thick algal-alginate film on the semi-conducting or conducting layer. Then the anode of the semi- conducting or conducting layer with the algal-alginate film is rinsed with sterile distilled water to remove the Sterile CaCl2.