That is unlikely. A brighter bulb would likely reduce contrast and saturation in picture quality, because the LCD was not designed for a brighter bulb. It is also unlikely that you could find a brighter bulb that would have the correct physical and digital properties.

However, if you have used the projector a lot, the bulb could be failing. If it is approaching the end of its life replacing it may produce a brighter image. Use the guides on this page to dismantle it.

Hope this helps!