A novel liquid crystal display (LCD) is alternately operable in an active display mode, in which its LED array is forward biased and the LEDs emit backlight, or in an inactive display mode, in which the LED array is reverse biased and the LEDs function as photo diodes that harvest the energy of ambient light to generate a photovoltaic (PV) current used to charge the battery of a device, such as a smartphone, in which the LCD is embedded. In one embodiment, the LCD is also alternately operable in a semi-active display mode, in which one or more selected segments of the LED array are forward biased, and the LEDs of the selected segments emit backlight, while one or more unselected segments are reverse biased, and the LEDs of the unselected segments generate the PV current to charge the rechargeable battery.