Solar colloidal battery is a kind of photoelectric semiconductor chip that uses sunlight to directly generate electricity, also known as "solar chip" or "photocell". It can output voltage instantaneously under certain light conditions, even if there is a loop. Able to generate electric current. In physics, they are called photovoltaics (PV for short).

　　Solar colloidal cell is a device that can convert light energy into electrical energy in response to light. Its principle is based on the photovoltaic effect of PN junction. This effect involves three main physical processes: First, the semiconductor material is irradiated with light. If the energy of the incident photon is greater than the energy gap, the photon is absorbed and the electron transitions from the valence band to the conduction band. Yes, the resulting imbalanced electron-hole pairs enter the space charge region of the PN junction through diffusion or drift. Charged by the built-in electric field, in the P zone, unbalanced electrons are attracted to the N zone, the boundary of the P zone gathers unbalanced holes, and the boundary of the N zone gathers unbalanced electrons to generate photoelectricity. The magnetic field opposite to the built-in electric field. When you connect a load to the PN junction, current will flow, which illuminates the PN junction and converts light energy into electrical energy.

　　Make a large-area PN junction to form the upper and lower contact leads of the solar cell. The back contact is generally formed by a large-area ohmic contact of deposited metal to reduce series resistance. The front surface is usually made into a grid shape because it is necessary to reduce the contact resistance and minimize the blocking of sunlight. After all, the current and voltage that a battery can provide is limited, so many batteries (usually 36) are connected in parallel or in series to form a solar panel.