An electrochromic device comprising from bottom to top: a substrate; a lower transparent conductor layer; a first electrochromic layer; an ion conductor layer; a second electrochromic layer; and an upper transparent conductor layer, wherein: (a) (i) the first electrochromic layer is a primary electrochromic layer and the second electrochromic layer is a secondary electrochromic layer, or (ii) the first electrochromic layer is the secondary electrochromic layer and the second electrochromic layer is the primary electrochromic layer; (b) at least one of the lower transparent conductor layer, the ion conductor layer and the upper transparent conductor layer is a planarizing layer having an upper surface roughness which is less than the upper surface roughness of an underlying layer in contact with a lower surface of the planarizing layer; (c) the upper surface roughness is defined as an arithmetic average of absolute values of peak-to-valley heights; (d) (i) the upper surface roughness of the planarizing layer is less than 90% of the upper surface roughness of the underlying layer or (ii) the upper surface roughness of the underlying layer in contact with the lower surface of the planarizing layer is greater than 50 nm and the upper surface roughness of the planarizing layer is 50 nm or less; and (e) the at least one planarizing layer reduces at least one of light scattering, haze, pinholes, cracks, and electrical shorts. a substrate; a lower transparent conductor layer; a first electrochromic layer; an ion conductor layer; a second electrochromic layer; and an upper transparent conductor layer, wherein: (a) (i) the first electrochromic layer is a primary electrochromic layer and the second electrochromic layer is a secondary electrochromic layer, or (ii) the first electrochromic layer is the secondary electrochromic layer and the second electrochromic layer is the primary electrochromic layer; (b) at least one of the lower transparent conductor layer, the ion conductor layer and the upper transparent conductor layer is a planarizing layer having an upper surface roughness which is less than the upper surface roughness of an underlying layer in contact with a lower surface of the planarizing layer; (c) the upper surface roughness is defined as an arithmetic average of absolute values of peak-to-valley heights; (d) (i) the upper surface roughness of the planarizing layer is less than 90% of the upper surface roughness of the underlying layer or (ii) the upper surface roughness of the underlying layer in contact with the lower surface of the planarizing layer is greater than 50 nm and the upper surface roughness of the planarizing layer is 50 nm or less; and (e) the at least one planarizing layer reduces at least one of light scattering, haze, pinholes, cracks, and electrical shorts. (a) (i) the first electrochromic layer is a primary electrochromic layer and the second electrochromic layer is a secondary electrochromic layer, or (ii) the first electrochromic layer is the secondary electrochromic layer and the second electrochromic layer is the primary electrochromic layer; (b) at least one of the lower transparent conductor layer, the ion conductor layer and the upper transparent conductor layer is a planarizing layer having an upper surface roughness which is less than the upper surface roughness of an underlying layer in contact with a lower surface of the planarizing layer; (c) the upper surface roughness is defined as an arithmetic average of absolute values of peak-to-valley heights; (d) (i) the upper surface roughness of the planarizing layer is less than 90% of the upper surface roughness of the underlying layer or (ii) the upper surface roughness of the underlying layer in contact with the lower surface of the planarizing layer is greater than 50 nm and the upper surface roughness of the planarizing layer is 50 nm or less; and (e) the at least one planarizing layer reduces at least one of light scattering, haze, pinholes, cracks, and electrical shorts.