An n-type dopant, like phosphorus, improves the electrical conductivity of a semiconductor over an undoped semiconductor by introducing an extra electron into an energy level very close to the conduction band in a photovoltaic device. This electron is then easily expelled into the conduction band. This is known as a donor, which, in simpler terms is orbital energy with high charge. On the contrary, the acceptor is the same with a low charge.
The key component of a solar energy generation device that quickly transforms sunlight into electrical energy is a photovoltaic (PV) cell. A p-n junction component makes up the solar cell.
The terms n-type and p-type refer to the positively charged holes produced by acceptor impurity atoms and the negatively charged electrons donated by donor impurity atoms, respectively.
What are N-Type Solar Cells?
A big area p-n junction is a solar cell. A thin p-type silicon layer that has been doped with boron sits on top of a much larger n-type silicon layer that has been doped with phosphorus in an N-type solar cell.
Both surfaces have electrical contacts applied. P-side refers to the front aspect that faces the sun. A clear adhesive, such as EVA, is applied over the antireflective coating to keep the front protective glass layer in place.
Why N-Type are rare?
The majority of solid solar cells on the market today are p-type. This is brought on by the p-cheaper type’s manufacturing costs. The history of solar cell development is presumably to blame for the factors. However, n-type solar cells can offer a significantly higher efficacy compared to p-type solar cells in terms of performance.
This is due to two major factors. First, boron (trivalent) poisoning is present in p-type material. In the presence of light and oxygen, boron goes through some undesirable processes that lower conversion effectiveness. The term for this is Light Induced Decay (LID).
What are the Disadvantages of P-Type Solar Cells?
Remember that sunshine causes an electron hole pair to become loose in order to comprehend the second drawback. The holes are minority carriers in this (the n-type area) if this occurs there.
By absorbing one of the free electrons, which make up the bulk of the carriers in this system, a hole could be filled while drifting. In this scenario, the solar energy absorbed will only heat the cell and be wasted as heat.
Also Read: What is a Dopant?
Our goal is to enable the holes to enter the depletion region, where the electric field will sweep them to the p-type substance and then onto the anode. In order to improve solar efficiency, minority carriers’ diffusion lengths must be as long as feasible. Now you know about donor.
Because the n-type cell is less impacted by minor impurities, the diffusion duration of minority carriers is longer in n-type cells than in p-type cells. N-type cells have a higher conversion rate because their minority carriers have a longer diffusion length. For this reason, the pertinent industry is heavily investing in research in this area to enable more economically viable n-type cell production.
