As an AI text-based model, I am unable to create visual diagrams. However, I can describe the working principle of a solar panel in simple terms for an 8th-class student.

A solar panel is made up of many small units called solar cells. Each solar cell is made of a semiconductor material, usually silicon. The solar cells are connected together to form a solar panel.

The working principle of a solar panel is based on the photovoltaic effect. When sunlight falls on the solar panel, it contains tiny particles of light called photons. These photons carry energy.

When a photon hits a solar cell, it can be absorbed by the semiconductor material. This absorption causes the electrons (tiny particles inside the material) to become excited and gain energy. These excited electrons are then able to move freely within the material.

The solar cell has two layers: the P-type layer and the N-type layer. The P-type layer has an excess of positive charges, while the N-type layer has an excess of negative charges. This difference in charges creates an electric field between the two layers.

When the excited electrons move within the semiconductor material, they are pushed towards the N-type layer due to the electric field. This movement of electrons creates a flow of electric current.

To make use of this electric current, the solar panel is connected to an external circuit. The current flows through the circuit, providing electrical energy that can be used to power devices or stored in batteries.

In summary, when sunlight falls on a solar panel, the photons in the sunlight are absorbed by the solar cells, causing the electrons to become excited and create an electric current. This current can be used as a source of clean and renewable energy.