Solar cell experiment Essay Example

must also be present; the top layer should have materials such as metal to permit light entry.

Solar cells rely on their metal bottom contact layer to function as a proficient conductor for the electricity produced by photovoltaic cells. These cells, which are typically composed of semiconductors like silicon, convert light into electrical energy through photon absorption and the subsequent liberation of electrons that have mobility.

When photovoltaic cells generate electric fields, they release electrons to follow a specific path. To utilize this current, metal contacts are placed at the top and bottom of the cell. If you're interested in understanding electron sharing, visit this resource on atom sharing. Silicon has 14 electrons but only four in its outer half-full shell. As a result of silicon sharing electrons with four other silicon atoms, a crystalline structure is created.

By adding impurities like phosphorus, unmodified silicon can be transformed into a more conductive material. The lack of free electrons in pure silicon makes it unsuitable for conducting, but the addition of phosphorus alters the bonding structure and introduces a free electron. This makes it an ideal material for use in solar cells.

The process of doping silicon with impurities such as phosphorus makes it easier to release electrons, specifically those belonging to phosphorus. This results in an increase in the number of free carriers, causing the silicon to become N-type with a negative charge due to the surplus of electrons.

By combining boron, which has a mere 3 electrons in its outer shell, with silicon, a P-type junction is formed resulting in a positive charge. This is due to the lack of an electron

producing a hole and leading to a positive charge on the silicon. When P-type and N-type silicon are mixed, it results in the formation of a barrier at the junction. This makes it difficult for electrons to cross over from the N-side to the P-side creating an equilibrium at the junction that involves an electric field separating both sides. While this electric field allows for electrons to flow from the P-side towards the N-side, it prohibits any movement in reverse.

When it comes to the cell's behavior, it resembles a diode which allows current flow solely in one direction - from p-type over to n-type. Assuming that a light photon possessing sufficient energy hits the cell, an electron along with a hole are usually let go. If this event takes place close to the electric field, then the N-side gets the electron while the P-side obtains the hole thus breaking neutrality. The outcome of this is that electrons will eventually return back to the P-side after being dispatched so as to bond with holes located on the N-side resulting in current flow. Ultimately, it is worth noting that it is thanks to the electric field of said cell that voltage gets generated.

Solar cells can only absorb around 15% of the energy from sunlight due to its polychromatic nature. This is because not all wavelengths possess enough energy to release electrons, resulting in some energy passing through without being utilized. Furthermore, excess energy in certain wavelengths can only partially be used to release electrons, leading to a loss of approximately 70% of total energy. The high internal resistance of silicon also contributes to this loss.

The investigation's

objective is to determine the elements that influence solar cell productivity. One technique for enhancing it is by utilizing antireflective coating on semiconductors. This layer acts as a barrier, preventing energy from bouncing off the glossy silicon surface and, consequently, decreasing losses by 5%.The experiment will be examining two variables, namely the voltage supplied and the distance of the lamp from the solar cell. These factors were selected as they are anticipated to have a substantial impact on generating precise and consistent data that can be presented in a linear graph. Two hypotheses have been created for this experiment. The first hypothesis postulates that there will be a reduction in output from the solar cell with an increase in distance between it and the lamp. The second hypothesis proposes that an increase in power will result in an escalation of output from the solar cell. It is assumed that there's a sustained energy supply from the lamp during variable investigation for hypothesis one.

The light intensity decreases when the lamp is moved from the solar cell because of the dilution of light concentration. The immediate surroundings of the lamp has a higher concentration of light that provides more energy to the solar cell. However, as the light energy spreads out, it covers a larger area resulting in less energy reaching the solar cell.