Data for the plots in the main text. Instructions for some data sets are contained within the Excel file. Detailed description: One Microsoft Excel file containing data for each plot in the main manuscript figures, as labelled. Photoluminescent data (1A) is measured through 355 nm laser illumination of a typical CdSxSe1-x nanowire at 7 different locations as shown in the image in the main text; intensities for each location are normalized to their respective maximum intensity. Photocurrent measurements (1C) are made applying bias between two electrodes toward the CdSe-rich end of a typical nanowire photodetector array, under the labelled irradiances by 490 nm light. Time response (1D) is of the same unit as measured for the photocurrent data, under illumination by a blue LED, pulsed at a frequency of 50 Hz. Calibration data (1E) is supplied for each unit (labelled as R"i", where "i" is the unit index) of a typical nanowire spectrometer with 30 units, consisting of the photocurrent measured under illumination at different wavelengths from 490 to 630 nm (spaced in the case of this example at increments of 5 nm) by a tunable Xe arc lamp source. Note that for the nanowire devices presented in Figs. 2A-D, 3F and 4G, a narrower sample spacing of 3 nm was used in the calibration. Note also that calibration photocurrents have been normalised for the purpose of more clearly illustrating the spread of cut-off wavelengths across the set of units. Spectral datasets (2A-D, 3F, 4G) are, as labelled, either measured from a conventional spectrometer (Thorlabs, CCS100 compact spectrometer, 350-700 nm) or reconstructed by a 30-unit or 38-unit nanowire spectrometer as described in the text using the calibration data and photocurrents measured from each unit whilst under illumination by the unknown light signal. Data for 2A-D and 3F have been normalized so as to better compare the conventional and nanowire spectrometers. Both sets of mapping data (3D, 4F) show in effect a data cube with 3 dimensions (x, y, wavelength). The x-y planes measure 30 x 30 pixels, with pixel size 300 µm x 300 µm for 3D and 20 x 10 pixels with pixel size 20 µm x 20 µm for 4F. The pixels are indexed in a raster fashion, such that, for example, pixels 1 to 30 in 3D correspond to the first row in the spectral image, while 31 to 60 correspond to the second row, and so on.