Apparatus for testing concentration-type solar cells

There is disclosed an apparatus for testing concentration-type solar cells. The apparatus includes a light source for emitting light, a focusing unit for focusing the light emitted from the light source and turning the same into a light beam, a testing unit for testing any one of solar cells of a wafer; and a wafer-positioning unit for moving the wafer horizontally and vertically, thus brining a targeted one of the solar cells into contact with the testing unit.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to concentration-type solar cells and, more particularly, to an efficient, effective and inexpensive apparatus for testing concentration-type solar cells.

2. Related Prior Art

Solar cells are popular for being environmentally friendly and economic in use. The efficiencies of solar cells are becoming higher and higher while the prices are becoming lower and lower. Therefore, solar cells are getting more and more attention. To increase the efficiency of a solar cell and reduce the cost of the same, more and more effort are made to develop concentration-type solar cells of III-V compounds. Therefore, there is a need for an efficient and effective apparatus to test these tiny concentration-type solar cells of III-V compounds. Such an apparatus is however expensive.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide an efficient, effective and inexpensive apparatus for testing concentration-type solar cells.

To achieve the foregoing objective, an apparatus includes a light source for emitting light, a focusing unit for focusing the light emitted from the light source and turning the same into a light beam, a testing unit for testing any one of solar cells of a wafer; and a wafer-positioning unit for moving the wafer horizontally and vertically, thus brining a targeted one of the solar cells into contact with the testing unit.

Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring toFIGS. 1 through 3, there is shown an apparatus for testing concentration-type solar cells according to the preferred embodiment of the present invention. The apparatus includes a light source1, a focusing unit2, a wafer-positioning unit3and a testing unit34.

The light source1may be a light-emitting diode (“LED”), a solar simulator, a halogen lamp or any other proper lamp for use in any ordinary instrument. The light source1is used to emit light.

The focusing unit2may be an aperture defined in a plate or a condenser lens. The focusing unit2is used to focus the light emitted from the light source1and turns the light into a light beam11.

As clearly shown inFIG. 2, the wafer-positioning unit3includes a first workbench31, a second workbench32and an elevator33. The first workbench31includes a slot311defined therein, a screw313disposed in the slot311and a driving element312operatively connected to the screw313.

The second workbench32includes a slot321defined therein, a screw323disposed in the slot321and a driving element322operatively connected to the screw323. The second workbench32is provided on the first workbench31. Although not shown, the second workbench32includes a nut attached to the bottom. The nut of the second workbench32is engaged with the screw313of the first workbench31so that the second workbench32is moved in a first direction when the screw313is rotated by the driving element312of the first workbench31.

The elevator33is used to support a wafer331. As clearly shown inFIGS. 4 and 5, the wafer331includes a lot of solar cells3311each in the form of a chip. Although not shown, the elevator33includes a nut attached to the bottom. The nut of the elevator33is engaged with the screw323of the second workbench32so that the second workbench32is moved in a second direction when the screw323is rotated by the driving element322of the second workbench32. The second direction is perpendicular to the first direction. Thus, the horizontal position of the wafer331can be changed because of the first workbench31and the second workbench32. The elevator33includes a driving element332operable to change the vertical position of the wafer331.

As clearly shown inFIG. 3, the testing unit34includes two probes341, a testing element342connected to the probes341and a computer343connected to the testing element342. Moreover, the computer343is connected to the driving elements312,322and332. The probes341are retained in position, horizontally and vertically.

To test any one of the solar cells3311of the wafer331(the “target”), the light source1emits light. The focusing unit2focuses the light emitted from the light source1and turns the same into a light beam11. At this instant, the wafer331is not in contact with the probes341. Under the control of the computer343, the driving elements312and322move the wafer331horizontally so that the target is right below the probes341. Under the control of the computer343, the driving element332lifts the wafer331and brings the target into contact with the probes341. The probes341acquire various parameters of the target such as the open circuit voltage, the short circuit current, the maximum voltage and the maximum current. Based on these parameters, the computer343calculates the fill factor and the photo-electric conversion efficiency of the target.

As discussed above, the present invention provides an efficient, effective and inexpensive the apparatus for testing concentration-type solar cells.