Quantity   Component name
1 × Amorphous Solar Cell The smaller the better.
1 × Tritium (3H) Light Tube The larger the better.
1 × Aluminum Foil For reflector and light blocking
1 × 100uF+ Capacitor For energy storage. Any larger will take a long time to charge, any smaller will not run the calculator for long.
1 × Switch For powering on the calculator
1 × Cheap Calculator Avoid ones with too many features as these may draw too much power. The LCD should be as small as possible.