Shares of GT Advanced Technologies (NASDAQOTH:GTATQ) have taken a beating since it was announced that Apple's (NASDAQ:AAPL) new iPhone 6 wouldn't include a sapphire cover screen as hoped. Shares dropped 13% on the day the products were announced and have fallen 25% since September 8.

GTAT Chart

GTAT data by YCharts

But if we take a step back and look at the company and its stock objectively this could be a great time to buy a temporary hiccup for investors. Here are the reasons investors should be excited about GT Advanced Technologies.

Apple demand is coming
The disappointment over sapphire not being the iPhone 6 cover screen material was way overdone. First, as I explained over the weekend the timeline GT Advanced Technologies had to build its sapphire plant made it nearly impossible that sapphire would be used for the cover screen. But this doesn't eliminate the upside for the company, and sapphire will still be used short-term for home buttons, camera covers, and throughout the new Apple Watch.

Apple Watch will use several sapphire components made by GT Advanced Technologies. Image Source: Apple.

It's really the Apple Watch that both companies have been gearing up for, and there are rumors that the iPod may get sapphire displays in the future as well. Long-term, I don't think Apple would prepay $578 million and house sapphire production within its own manufacturing plant if the technology wasn't in its long-term plans for multiple product lines, including the iPhone. There's still upside here, even if the market is looking past it for the time being.

Solar refresh cycle
Don't forget that the solar industry was actually where GT Advanced Technologies got most of its revenue until recently, and it's still a big part of the company's future. Since 2012, solar manufacturers have been in a holding pattern because supply greatly exceeded demand, but that's about to turn around and the refresh cycle for equipment could be huge.

This year, it's estimated that 50 GW of solar will be installed around the world compared to 70 GW of supply. But within that there's far greater demand for high efficiency modules than cheap, low efficiency modules, and as companies see overall demand exceed supply they'll want to upgrade to the latest and greatest equipment.

GT Advanced Technologies has that equipment, from polysilicon down to the HiCz process it says can make 22%+ efficient monocrystalline cells. Demand for HiCz has yet to materialize, but that could change if solar companies begin to upgrade equipment. GT Advanced Technologies was the one that helped build out capacity for manufacturers like Trina Solar, Yingli Green Energy, and LDK Solar, who built some of the largest solar capacities in the world. 

The company also introduced Merlin, a metallization process that's expected to improve panel efficiency and interconnection by replacing bus bars with a flexible grid of conductors. Merlin isn't a known commodity but it provides further upside for the company.

Foolish bottom line
Investors were disappointed last week that sapphire wasn't going to be used as the iPhone 6 cover screen but that was a short-term reaction to a long-term opportunity with Apple. In solar, GT Advanced Technologies has billions of dollars in potential as manufacturers upgrade and grow capacity over the next decade.

Don't let the market's short-term reaction cloud the long-term potential of this company. The future is still bright for GT Advanced Technologies.

Travis Hoium manages an account that owns shares of Apple. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.