MIT researchers Jie Bao and Moungi G. Bawendi published "A colloidal quantum dot spectrometer" paper in Nature journal. "The new quantum dot spectrometer deploys hundreds of quantum dot materials that each filter a specific set of wavelengths of light. The quantum dot filters are printed into a thin film and placed on top of a photodetector such as the charge-coupled devices (CCDs) found in cellphone cameras." Potentially, a fairly accurate spectrometer can be cheaply created in a compact form.
Here is a example of filters made with this method:
and here is the doublet peaks resolution of the proposed quantum dot spectrometer on the right vs HR2000 spectrometer as a reference on the left: