More signs on Friday that the world of flexible, building-integrated thin-film solar is a hard market to break into, this time from Ascent Solar. The Colorado-based maker of flexible copper-indium-gallium-selenium (CIGS) photovoltaic materials announced this morning that it is shifting its market focus from building-integrated applications to niches like military and vehicle applications. It also announced it was cutting staff and operations expenses and replacing its CEO, all news that led to its shares falling about 25 percent in morning trading. Ascent said it could get better margins for its products in specialty markets — another way of saying it can’t sell its technology into the building rooftop market at prices that compete with old-fashioned, rigid solar panels. The dream of flexible solar materials that can be integrated into roof tiles and the like remains a long way off, though many startups are aiming for it. San Jose, Calif.-based SoloPower has a CIGC product on the market, and Tucson, Ariz.-based Global Solar Energy also wants to sell flexible CIGS materials. Well-funded Massachusetts startup Konarka has been working on organic flexible solar materials for a decade, but has yet to reach its vaunted high production capacities.