Yes, more light. The plant needs to "see" the sun for hours a day year round. There's no way you'll get more than half a day of it indoors (except in just the right location at just the right time of year) and there's no way it will be direct indoors (regular window glass cuts a lot of the UV out) but you need to provide the absolute maximum possible amount. The more, the better. Right in front of your sunniest southerly facing window, assuming you're in the northern hemisphere.
