Most photoelectric effect experiments require an electroscope for observing electron emissions. Although these can be purchased, a homemade electroscope is more cost-effective. Cut two strips of aluminum foil 1-by-4 cm. Unfold a paper clip to form an S shape. Place a strip of transparent tape over the center of an index card and thread the paperclip halfway through the tape strip. Poke the lower curve of the clip through both aluminum strips so they hang beside each other. Insert the device into a glass jar. The index card should rest on the jar mouth so the strips are suspended. Touch a charged item to the jar to test the electroscope. The foil strips should repel each other.
A variety of factors infulence photoelectron emission, including light frquency and color. Gather an electroscope, permanent marker, sheet metal, sandpaper, short jumper wire, five different-colored light filters and a source of incandescent light. Remove all other light sources from the room. Rub the sheet metal with sandpaper before placing under the light source and connect to the electroscope with the jumper wire. Observe the effect of the light on the electroscope leaves and record data. Mark on the glass jar the point to which each leaf edge extends during repulsion. Repeat the experiment, inserting a different filter between the light and metal each time and record results.
Rub a piece of zinc metal with steel wool and attach the metal to the electroscope with a short jumper wire. Remove all light from the room except for a carbon arc lamp, which should shine directly on the zinc. Observe the electroscope leaves and record data before discharging. Turn off the ultraviolet light and turn on the room light. Compare the reaction in the electroscope leaves and record differences from the carbon arc lamp. Discharge the electrode, turn out the room light and switch the ultraviolet light on. Hold a sheet of glass, treated to keep out ultraviolet rays, between the carbon arc lamp and the zinc. Record final data and determine if experiment results support Einstein's conclusions about photons.
Photoelectric effects serve practical use in the form of solar cells. Test for solar cell ideal operating conditions with three 1-Watt solar cells and scientific instruments. Build two tables from 2-by-4 lumber and plywood. One table should be 12 inches high and the other should be 24 inches high. Set a metal plate on the ground in direct sunlight and place the two tables near the plate. Under the taller table, place a plastic tub filled with ice. Set a solar cell on each of the three surfaces and leave for 30 minutes. Retrieve the cells and place in a dark room to observe the effects of a heated solar cell, solar cell with ventilation, and a cooled solar cell. Test results are most accurate when performed at noon on a day when the temperature is near 70 degrees Fahrenheit.