What is a Solar panel made of?
What is a Solar panel made of?
Doped silicon wafers with silver contacts, sealed between low-iron glass and a plastic backsheet in an aluminium frame.
By mass a panel is mostly glass and aluminium, and the silicon is a small fraction — which is why panels are heavy, why they are cheap, and why recycling them recovers a lot of low-value material and a little high-value silver. Output degrades slowly and predictably, typically a few tenths of a per cent a year, and warranties are written around 80-85% of rated output at 25 years. The other thing worth knowing is that panels lose efficiency as they get hot: rated power is measured at 25 °C cell temperature, and a roof panel in summer sun routinely runs 20-30 °C above ambient, so a cold bright day can outproduce a hot one.
Component by component
| Part | Material | Why that material |
|---|---|---|
| cells | crystalline silicon wafers doped with boron and phosphorus | The junction between the two doped layers is what separates light-generated charge; silicon is abundant and its bandgap suits sunlight well. |
| contacts | screen-printed silver paste fingers and busbars | Silver is the best conductor and prints finely, and it is the material cost the whole industry works hardest to reduce. |
| encapsulant | ethylene vinyl acetate film, laminated under vacuum | It bonds the stack and keeps moisture off the cells; when it yellows or delaminates, output falls and the panel is finished. |
| front glass | low-iron tempered glass, 3-4 mm | Iron gives ordinary glass a green tint that absorbs useful light; low-iron glass transmits a couple of per cent more. |
| backsheet and frame | a fluoropolymer-PET laminate or a second glass sheet, in an anodised aluminium frame | The frame carries the wind and snow load; glass-glass panels last longer but weigh considerably more. |
| junction box | a sealed box with bypass diodes | Without bypass diodes, one shaded cell would throttle the whole string and heat up dangerously as a resistor. |
Other electronics objects
- Alkaline battery Zinc powder and manganese dioxide either side of a potassium hydroxide paste, in a steel can.
- Smartphone screen Chemically strengthened aluminosilicate glass over a touch layer and an OLED or LCD panel, with an oil-shedding coating on top.
- LED bulb Blue LED chips under a yellow phosphor, plus a driver circuit and a heat sink — and it is the driver that dies.
- Touchscreen A grid of transparent electrodes measuring the tiny capacitance your finger adds — which is why gloves fail.
- Computer keyboard ABS or PBT keycaps over either a silicone rubber dome on printed film, or individual mechanical switches.
- Headphones A neodymium magnet, a coil of copper wire and a thin plastic diaphragm — a loudspeaker shrunk to fit an ear.
- Loudspeaker A paper or plastic cone hung on a rubber surround, driven by a coil in a magnet gap.
- Computer mouse An ABS shell around a tiny camera taking thousands of pictures a second, plus two clicky microswitches and PTFE feet.
Common questions
- What is a Solar panel made of?
- Doped silicon wafers with silver contacts, sealed between low-iron glass and a plastic backsheet in an aluminium frame.
- What is the cells of a Solar panel made of?
- Crystalline silicon wafers doped with boron and phosphorus. The junction between the two doped layers is what separates light-generated charge; silicon is abundant and its bandgap suits sunlight well.
- What is the contacts of a Solar panel made of?
- Screen-printed silver paste fingers and busbars. Silver is the best conductor and prints finely, and it is the material cost the whole industry works hardest to reduce.
Related pages
- Alkaline battery Zinc powder and manganese dioxide either side of a potassium hydroxide paste, in a steel can.
- Smartphone screen Chemically strengthened aluminosilicate glass over a touch layer and an OLED or LCD panel, with an oil-shedding coating on top.
- LED bulb Blue LED chips under a yellow phosphor, plus a driver circuit and a heat sink — and it is the driver that dies.
- Touchscreen A grid of transparent electrodes measuring the tiny capacitance your finger adds — which is why gloves fail.
- Computer keyboard ABS or PBT keycaps over either a silicone rubber dome on printed film, or individual mechanical switches.
- Headphones A neodymium magnet, a coil of copper wire and a thin plastic diaphragm — a loudspeaker shrunk to fit an ear.
- Loudspeaker A paper or plastic cone hung on a rubber surround, driven by a coil in a magnet gap.
- Computer mouse An ABS shell around a tiny camera taking thousands of pictures a second, plus two clicky microswitches and PTFE feet.
- Pencil Stationery and paper
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Paper Stationery and paper
- Glass Building materials
Sources
- Typical range compiled from manufacturer specifications — At One Place