Nano solar cells

TASKS

1.What's the Point?

Show your understanding of the reading (listening). Based on the text, choose the best answer to

complete the following statements.

1. The reason that solar power is not used widely today is that

a. current solar technology cannot produce enough electricity

b. solar energy is more expensive to use than other forms of energy

c. solar power is not available everywhere in the world

d. solar energy is unpopular

2. Wider use of solar power may now be possible because.

a. new materials have been developed

b. new production techniques have been developed

c. a new kind of solar cell can be integrated with other building materials

d. All of the above are correct.

3. Solar cells convert sunlight into useful energy in the form of

a. intense heat

b. bright light

c. invisible radiation

d. electric current

4. The new nano solar cells will be made of.

a. a plastic-based material

b. a silicon-based material

c. a very thin metal material

d. All of the above are correct.

5. The composite material of nano solar cells is semiconducting nanorods.

a. half

b. less than half

c. more than half

d. None of the above is correct.

6. Alivisatos and his research team are now working to improve the efficiency of nano solar cells with.

a. a new nanorod material and orderly placement of nanorods in the composite

b. a new nanorod material and random mixing of nanorods in the composite

c. random mixing of nanorods and painting the solar cells on a surface

d. orderly placement of nanorods and thinly rolled sheets of solar cells

7. With nanotechnology, solar cells can be.

a. efficient but difficult to produce

b. expensive but still profitable

c. inexpensive and widely available

d. inexpensive but unpopular

2. Understanding Words and Phrases:

Following are excerpts from the text you have just read(listened to). Based on context, choose the correct meaning of the underlined expression. The underlined expressions appear here in the same order as in the text; they are also underlined in the text for easy reference.

1. "But harnessing its energy depends on silicon wafers...."

a. controlling and using

b. buying and selling

c. creating and destroying

d. raising and lowering

2. "... silicon wafers that must be produced by the same exacting process used to make computer chips."

a. exactly the same

b. scientifically advanced

c. needing pure water

d. requiring great care

3. "... an energy source best suited for satellites and other niche

applications."

a. invented

b. rejected

c. inexpensive

d. appropriate

4. "Other researchers have attempted to concoct solar cells from these plastic materials...."

a. to prepare by mixing

b. to invent

c. to shape into a cone

d. to cut out

5. "But several tricks now in the works could further boost performance."

a. inform

b. increase

c. bring back

d. damage

6. "The scientists are also ali gning the nanorods in branching assemblages that conduct electrons more efficiently than do randomly mixed nanorods."

a. making bigger

b. marketing abroad

c. manufacturing

d. arranging in proper order

7. "... he sees 'no inherent reason' why the nano solar cells couldn't eventually match the performance of top-end, expensive silicon solar cells."

a. upside down

b. among the best

c. difficult to find

d. most complex

8. "He predicts that cheaper materials could create a $10 billion annual market for solar cells, dwarfing the growing market for conventional silicon cells."

a. making seem small

b. collaborating with

c. destroying magically

d. helping cheerfully

LESSON 45

GREAT SCIENTISTS & INVENTORS

Vocabulary

Enormously devastating bomb

Fission of the uranium nucleus

Have scant effect on

Mere

Stepping-stone

To stem from

To reconcile the laws

The text is taken from http://www.oppapers.com/essays/Albert-Einstein/73388

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