Basics of Third Generation Solar Cells and Their Types

Third Generation Solar Cells :

They are proposed to be very different from the previous semiconductor devices as they do not rely on a traditional p-n junction to separate photogenerated charge carriers.

For space applications quantum well devices (quantum dots, quantum ropes etc.) and devices incorporating carbon nanotubes are being studied with a potential for up to $45 %$ production efficiency.

For terrestrial applications, these new devices include photoelectrochemical cells, polymer solar cells, nanocrystal solar cells,dye sensitized solar cells and are still in the research phase.

Types of Third Generation Solar Cells :

A.) Organic Photovoltaic Cell :

1. The solar cells based on organic semiconductor can provide a low cost alternative for photovoltaic solar.

2. The thickness of the active layer of organic solar cells is only $100 nm$ thin, which is about $1000$ times thinner than the crystalline silicon solar cells, and it is about 10 times thinner than the current inorganic thin film solar cells.

3. In the low material consumption per solar cell and the relatively simpler cell processing of organic semiconductors, there is a large potential for low cost large area solar cells.

4. Due to this reason, there is a considerable interest in organic photovoltaic devices.

5. Their principal advantage is that they are flexible and can bend without breaking, unlike $Si$, which is brittle.

6. They are also very light and cheap.

7. They may folded or cut into required size and can still be used.

B.) Dye Sensitized Solar Cell (DSSC):

1. Dye Sensitized Solar Cell converts any visible light into electrical energy.

2. The dye sensitized solar cells can be considered as a thin film solar cell device. This technology is not yet commercialized but is on the verge of commercialization.

3. The dye sensitized solar cells can be made flexible. It has a very good potential for being a low cost effect solar cell technology.

4. This is mainly possible because of the large availability and low cost of the ingredient material as well as due to the low processing temperatures.

5. The dye sensitized solar cells is a photo-electro-chemical device. In its operation it involves a photon, an electron and a chemical reaction.

6. The operation of dye sensitized solar cell is considered similar to that of a photosynthesis process.

7. The DSSC has a number of attractive features; it is simple to make using conventional roll-printing techniques, is semi-flexible and semi- transparent which offers different type of uses not applicable to glass-based systems, and cost of most of the materials used in DSSC are very low.