A number of semiconductor companies are at risk after China decided to impose new export controls on gallium and germanium, two rare elements used to make semiconductors, investment firm Wells Fargo said, including Wolfspeed (NYSE:WOLF) and Qorvo (NASDAQ:QRVO). Analyst Gary Mobley, who has an overweight rating on Wolfspeed (WOLF), said the North Carolina-based chipmaker could see constraints for gallium nitride, or GaN, on silicon carbide production. Mobley added that Wolfspeed (WOLF) is the number one supplier of materials for gallium nitride, with companies like Qorvo (QRVO), NXP Semiconductors (NXPI) and others buying it from suppliers like Wolfspeed. Wolfspeed (WOLF) shares…