Whats solar power?
it is very clean power generation mechanism. solar cell is made from Silicon( Si) . it is two different semiconductors and the antireflection film constituted , the electrodes. (For details, please see the mechanics of solar power).
Solar cell structure is simple . But there are still problems, such as cost.
this site explain such benefits and problems. And, we think about the future of solar power.
Classification of solar power
his page explain about detail of solar cell. First, the solar cell's structure. modules is constructed by gathering the cell.
he cell is made from different semiconductor (n-type and p-type) of the conduction. shape is about 0.15mm thick, and square 10 ~ 15cm. this cell the electric current is 3A and the voltage is 0.5V, the power is about 2W.
Module is about 1 ~ 1.5m rectangle , a thickness of 5cm and a generating capacity of about 150 ~ 180W.
Thing to be installed this module on the roof is called array.
How use the solar cell part1
How make power generation on the solar cells ? （description Video is in the gallery.) Solar cells as described in the preceding pages, has n and p type semiconductor (Figure 1).
(Click to enlarge)
These two different semiconductors which is p and n-type are joining succesive . The n-type semiconductor have minus electrons(-e) . The p-type semiconductor have electrons missing hole(+hole).(Figure 2) + Hole can be thought of moving.
How use the solar cell part2
when this electrons join with p -type n -type semiconductors , +hall and -e scatter on n-type and p-type.(Figure 3) it called the depletion layer.。
The depletion layer have ion which is charged to the + side on n-type semiconductor and to the -side on p-type semiconductor . Therefore, it arise electric field (electric power) in -side from the + side (the p-type to n-type) .
Then,this electric field has the role of the wall preventing the movement(Figure 5) which is the + Hall moves on p-type from the n-type and the -e moves on n-type from the p-type
(Click to enlarge)
How use the solar cell part3
For this situation, the p-type n-type charge equilibrium is stable. However,when irradiate the depletion layer in this state,-e and hole is turned out of the joint part. (Figure 6)
-e move to n-type semiconductor and hole move to p-type semiconductor by arisen electric field.So electromotive force arise. This electromotive force continue while irradiate.Therefore it generate electricity (Figure 7). it can be used semi-permanently irradiating .
(Click to enlarge)
Type of Solar part1
Solar cell used matter is not only Silicon semiconductors , but other matter . It is the periodic table (see below) .As you can see, and is an element of group 14.
So solar cell is used such as germanium and carbon too. Looking at the different solar cell material, "silicon-based" "compound" "organic" can be divided into.
periodic table(Click to enlarge)Type of Solar part2
This site take up silicon. Silicon is two types which are crystal single and plural. single one is most popular. it's transformation efficiency is 15-19%. But there is cost problem.Because making place is complicated. It's prolem is solved plural one. it's transformation efficiency is 12-16%. (There are pictures in the gallery.)
Utility value and promising of solar power part1
This solar power generation compared to other methods How much value of using? First,the advantage of solar power is noemissions at all the CO2,because it use sunshine.
It is safest the other which are nuclear and thermal,hydro power. And It is not limiter place than wind and tidal powerr. The individual can use it because it is small size. What is disadvantage? It is cost be expensive And limited to weather and time.
Improvement cost problem is not only bring down,but transformation efficiency up. It's research proceed .
