A University of Southern California team has produced flexible transparent carbon atom films that may have great potential for a brand new variety of solar cells.

In a paper recently published by the journal ACS Nano, researchers stated that organic photovoltaic (OPV) cells have been proposed as a technique to achieve low priced energy due to their ease of manufacture, light weight, and compatibility with flexible substrates.

The new work shows that graphene, an extremely conductive and highly transparent kind of carbon made up of atoms-thick sheets of carbon atoms, has high possibility to fill this role.

While graphene’s existence has been known for many years, it has only been studied extensively since 2004 because of the impracticality of manufacturing it in high quality and in quantity.

The University of southern California team has produced graphene/polymer sheets ranging in sizes about 150 square centimeters that in turn can be used to create dense arrays of flexible organic photovoltaic (OPV) cells.

These organic photovoltaic (OPV) devices convert solar radiation to electricity, although not as efficiently as silicon cells.

The energy provided by sunlight on a sunny day is about 1,000 watts per meter square, for every 1,000 watts of sunlight that hits a square meter part of the standard silicon solar cell, 14 watts of electricity will be generated, Organic solar cells are less efficient; their conversion rate for that same 1,000 watts of sunlight in the graphene-based solar cell would be only 1.3 watts.

But what graphene organic photovoltaic (OPV) lack in efficiency, can potentially be compensated by its lower price and, greater physical flexibility.

Researchers think it may eventually be possible to cover with inexpensive solar cell layers extensive areas like newspapers, magazines or power generating clothing.

In the meanwhile Prof. Ruoff and his colleagues of the mechanical engineering department at the University of Texas at Austin, are studying the basic science in the development of graphene-based ultracapacitors for usage in electronics and various fields.

Prof. Ruoff says batteries are relatively slow, they can store energy but take time to charge up, and then they distribute energy slowly, over time.

Ultracapacitors can be charged very quickly, within seconds, and discharge in a short time, but, today, they can’t store very much electrical energy.

The development of stable and less costly ultracapacitors is seen as a key step in using wind or solar-generated power, particularly if researchers can find solutions to enable capacitors to store energy longer, that is not yet possible.

Even with their current storage capacity, the graphene devices could provide quick energy when needed in certain situations on the green way.

They could be used, for example, to absorb heat generated in braking an automobile or train, and store it for a short time, and then use it for the electrical needs of the vehicle (i.e. starting the auto or acceleration)

About the writer - Sophia H. Walker writes for the solar battery charger blog, her personal hobby site related to tips to help individuals save electricity using solar powered energy for small accessories.

Interested in stepping-up your black & white game?

Black and white photography can sometimes be way better un revealing the whole composition and photographers vision than colored.

Here are five tips to get you going in the right direction.

PRACTICE PRACTICE PRACTICE

An experienced black & white photographer can see the world without color. Or probably in two only colors and their derivatives. They’ve trained their mind to pick up contrast and tone while blocking the distraction of colors.

This isn’t a skill that you can pick up in a short amount of time; it’s something that comes naturally in time.

I can’t say that I’m gifted enough to have monochrome vision, but I have been able to notice certain scenes and subjects that would lend themselves to black & white.

One way to help train your brain is to make a conscious effort — in other words, practice.

Practice makes perfect, as you know. So don’t be lazy, try to practice as much as you can. Nothing comes just right away.

FOCUS ON CONTRAST

Black & white photography is about the black, the white, and all the tones in between. The human eye is built to pick up two things: light intensity and color. When you remove the color, your eyes become more sensitive to the light intensity. We naturally pick out areas of contrast — it’s how we distinguish one thing from another. As a black & white photographer, your main objective is to make your point with shades of gray. Use contrast to show your onlookers what’s important and what’s not. Seek out scenes that naturally show signs of high contrast, and your black & white photos will be more compelling right from the start.

FOCUS ON TEXTURE

Texture is really just a form of contrast, but it is perceived quite differently. If you think about it, texture is the regular or irregular pattern of shadows and highlights at various intensities. Black & white photos really lend themselves to texture because color generally add another layer of complexity, thus masking most subtle textures. Look for areas of interesting texture that can be photographed by zeroing in on specific surfaces and examining them for signs of patterned contrast.

The choices you make in post-processing can really make a difference in the texture too.

CAPTURE IN COLOR

This is mainly aimed at digital photographers… If your camera gives you the option of shooting in color or black & white, NEVER shoot in black & white. The camera is really capturing color, then converting to black & white. Photo editing software can do a much better job at the conversion, and you’ll have more flexibility on the output of the final image. It’s really amazing how different a photo can look solely based on the post-processing, so it’s best not to limit yourself before the photo even makes it out of the camera.

The one exception to this rule is if you wanted to use the black & white capture to give you a preview of what the scene might look like as a monochrome image. It may help you identify good black & white scenes more immediately, but once you find your shot switch back over to color capture and shoot it again.

USE COLOR FILTERS

Black & white film photographers make use of color filters to change the captured tones in their photographs. Ever see those monochrome images with dark skies and puffy white clouds? That’s not natural; it requires the use of color filtering to produce the desired effect.

Using an actual color filter with a digital camera is perfectly acceptable and it has its merits, but it’s not completely necessary. Software like Photoshop has the ability to apply non-destructive color filters. It also has the ability to produce the same results as a color filter during the black & white conversion.

When to Shoot

Many digital photographers actually prefer to shoot images for Black and White in low contrast situations. So an dark or overcast day can be a great time to shoot out door shots.

Ironically these are the days that those who shoot only in color sit at home complaining about the ‘poor light’. So next time you find yourself with a dark and gloomy day - shoot some black and white shots.

Composition

Most of the general tips on how to compose or frame a good shot apply just as well to black and white photography as they do when shooting in color - however the main obvious difference is that you’re unable to use color to lead the eye into or around your shot. This means you need to train yourself to look at shapes, tones and textures in your frame as points of interest. Pay particularly attention to shadows and highlights which will become a feature of your shot.

So if you’re interested in pursuing a little black & white photography, really think about these things — before, during, and after you shoot. Anybody can produce black & white photos, but it takes a little more thought and skill to produce good black & whites.

As I’ve already mentioned blurred photos are often the result of shaking hands, especially if you shoot in low-light conditions (read more about Low Light Photography), when a camera is set at a low shutter speed. But even in daytime when there is enough light, you can end up with blurred images if your camera is not firmly fixed. Images that look sharp or relatively sharp on the LCD display, can turn into completely washed out photos on the computer monitor or in prints.

That is why the first task of any aspiring photographer is to learn holding a camera properly. Point-and-shoot digital cameras are small and light, that is why the problem of shaking hands arises usually because a photographer does not know how to hold a camera for optimal results.

HOW TO PREVENT SHAKING-HAND EFFECT

1. If you use an optical viewfinder and keep your camera in a proper way (look the pictures below), you can easily follow moving objects, for example children playing sport games and get sharp images.
      

Hold your camera with      Holding a camera with
two hands. Keep your       one hand will NOT give
arms tight to your body    necessary steadiness.

2. If you use an LCD monitor, your camera is in a less stable position, that is why in this case it is especially important to firmly hold a camera and keep your arms close to your body to provide stability. You can also try to stretch out your arms and your camera will be in a more stable position compared to half-bent arms. Hold a camera firmly when you press the shutter button.

Press your arms tight         When you hold a camera     Do not press the shutter
to your body to provide     with one hand, a camera      button too hard, otherwise
stability to your camera.     will shake more.                  the image will be blurred out.

3. Use a tripod. It is a must to have accessory for any photographer. It will allow you to get sharp images of people and nature in daytime and at night. Read the series of articles about a TRIPOD:
- Tripods: 5 arguments for
- Camera tripod: advantages
- Tripod: for landscape, panorama and infrared photography
- Tripod: advantages

If you do not have a tripod, you can lean against a wall or a tree, or put a camera on any surface. Using a remote release or a self-timer will make your shots perfectly sharp.

Use a tripod (there are             Lean against a tree          Put your camera on
tripods that allow rotating        or a wall                           a table and use a
a camera around)                                                            remote release.