Archive for August, 2009

Making it for the first time in Modeling

Friday, August 28th, 2009

It is not the easiest of tasks to showcase your talent in the world of acting and not every actor gets this opportunity. If you are going to wait for the right opportunity to come and tap your shoulders then remember that there is a long wait ahead you. With the stiff competition you face, you are made to grabt at any chance which comes to you irrespective of how good it is. Call yourself the luckiest person on earth if your first opportunity turns out to be the best and you should never let it go. Only when such a situation comes to you the very first time, you would realize how hard it is make the best use of it and put your best into it. In fact, if you were keen enough you would’ve realized how hard it is when you see actors change themselves for every movie. They have to be completely new for every role they take up with a new accent and appearance. It is difficult for any common man and actors are common men too. This would make it clear that all the name and fame earned by an actor has not come over night and it has taken him years of consistent hard work to bring them to his door step.

For someone who is just been into modeling, things get even tougher. This is because you hardly know what is expected from you and what has to be delivered. This creates an imbalance in your mind and you should be mentally very strong to handle the pressure of being on stage for the first time.

One good way to get you out of all this trouble is to try acting to yourself in front of a mirror imagining doing it in front of the camera. This way you can improve your performance. You can also go for taping your performance if you find it uncomfortable with a mirror. This is one common technique which every actor practices as a part of his profession. Once you have made it up to this level, just tell yourself how much it has taken you to reach so far, to motivate yourself. Other than this, go for an outing and relax yourself before the final showdown.

What is Dye sensitized solar cell efficiency?

Sunday, August 23rd, 2009

Dye sensitized solar cell efficiency is a measure to characterize a DSSC. It is the ratio of the total electric power produced to a particular solar energy provided to the cell expressed as a percentage. In simpler words dye sensitized solar cell efficiency can be put down as the amount of electric power produced for a particular amount of solar light that is shining on the cell. The term dye sensitized solar cell efficiency helps us understanding the nanostructure of the dye sensitized solar cell. In the case of a dye sensitized solar the surface available for sunlight is large because of its nanostructure. Therefore there is every possibility that a photon will be absorbed by the dye and it is immediately converted into an electron.

The loss of energy is very little in the case of a dye sensitized solar cell and it is generally lost when the photon is transferred from the photo anode to the electrolyte. This loss is around 10% of the total photons excited and is relatively very less compared to other electrical energy generating systems.

The amount of electricity generated by a dye sensitized solar cell depends upon the number of photons absorbed and this largely depends on the absorption spectrum of the dye

Construction and Working of a Dye sensitized solar cell

Tuesday, August 18th, 2009

The construction of a Dye sensitized solar cell is fairly simple and can be easily explained. In general, a dye sensitized solar cell consists of the following parts which are listed in a sequence:

Photo anode
Semiconductor layer comprising of the dye
Electrolyte layer
Photocathode

Different materials have been experimented till date on these components of a dye sensitized solar cell and each material is found to produce a particular efficiency, within its own constraints. The popular materials which are used for the photo anode in the case of dye sensitized solar cell are ITO coated glass and FTO coated glass. These are also called as conductive glasses in general and conduct a fair amount of electricity generated without great loss.
The semiconductor layer popularly used is Titanium dioxide and nano titanium dioxide is mostly used. The particle size of this titanium dioxide is less than 100nm. This titanium dioxide layer is coated on the dye and the sensitized dye, also known as molecular sensitizer is absorbed on its surface. In the case of dye sensitized solar cell the popular dye used is a Ruthenium based Polypyridine dye. Ruthenium is generally preferred because of its longevity and prevents degradation of the dye sensitized solar cell.
Next is the electrolyte layer. The electrolyte layer is used for transferring the charges from the photo anode to the photo cathode and the efficiency of the dye sensitized solar cell mainly depends on the performance of the electrolyte. Different materials with the required properties are continuously experimented and the type of electrolyte depends upon the choice of the cell.
The photocathode is common in the case of most dye sensitized solar cells and the widely preferred one is made up of platinum metal.

Working of a dye sensitized solar cell:

The light rays which fall on the photo anode excite a photon when it strikes the dye coated on the surface of Titanium dioxide and this excited dye results in the injection of an electron in the semiconductor layer of titanium dioxide. The dye therefore loses one of its electrons and in order to get back its lost electron it takes one from the electrolyte and this process happens very quickly. The electrolyte which is one electron short diffuses and moves to the bottom of the cell where it gets back its lost electron from the photocathode as it has flown through the external circuit thereby constituting an electric current in the circuit. Thus a dye sensitized solar cell generates electricity.

What is a dye sensitized solar cell?

Thursday, August 13th, 2009

Dye sensitized solar cell also called as DSSC is a kind of thin film solar cell that is used to produce electricity from sunlight. It was invented by Michael Gratzel in the year 1991 and so dye sensitized solar cell is also called as Gratzel cell. It makes use of the light energy from the sun and converts them into electricity with the help of semiconductors, a photocathode, a photo anode and an electrolyte. Dye sensitized solar cell is an extremely promising one in the field of Solar energy as it is low cost and highly efficient compared to conventional solar cells. A lot of research is undergoing currently in the area of Dye sensitized solar cell technology and it is expected to one of the prospective areas in the field of renewable energy.