The fifth Google Nexus phone. Officially announced on October 31, 2013, it sports a 4.95" 1080p display, a 2.26 GHz Snapdragon processor, and LTE support. Powered by Android 4.4.2, KITKAT. Manufactured by LG.
This is a common problem, had the exact issue with my nexus 5. What I found worked was tapping the home button against the table and over time whatever was causing it to stick went away and hasn't had issues with the power button ever since.