Bonds issued pursuant to § 3-20 or sections 13b-74 to 13b-77, inclusive, may be designated by the Treasurer as college savings bonds. Bonds so designated, and any interest accruing thereon, shall be payable in one payment at maturity on a fixed date. Such college savings bonds shall mature not less than five years nor more than twenty years from the date of issuance, unless the State Treasurer determines otherwise, and shall be subject to such financial incentives as may be otherwise provided.