Techniques for providing plant growth lights with improved performance and cost are discussed herein. Some embodiments may provide for a light emitting diode (LED) flip chip chip-on-board (COB) module for optimizing plant growth, including: a circuit board； ultraviolet (UV) LED flip chips connected to the circuit board； a royal-blue phosphor or fluorescent layer covering a first portion of the UV LED flip chips； and a deep-red phosphor or fluorescent layer covering a second portion of the UV LED flip chips. The royal-blue phosphor or fluorescent layer absorbs UV light generated by the first portion of the UV LED flip chips and converts the UV light into broad-band light in royal-blue spectrums. The a deep-red phosphor or fluorescent layer absorbs UV light generated by the second portion of the UV LED flip chips and converts the UV light into broad-band light in deep-red spectrums.
