This top company is a top pick for 2020 and on the Goldman Sachs Conviction List of favorite stocks to buy. First Solar Inc. ( NASDAQ: FSLR ) is the largest vertically integrated solar manufacturer in the United States. The company uses a specialized cadmium telluride (thin film) based panel, which is different from most other panels, which are silicon based. First Solar engages in manufacturing and has planned 6 GW of capacity by 2020, with revenues increasingly coming from module sales.