Phosphor, manufacturing method thereof, and light-emitting device using the phosphor

A phosphor represented by the following formula (I):

• Ka(Si1-x,Mnx)Fb;
• wherein a, b and x are numbers satisfying the conditions of 1.5≤a≤2.5, 5.5≤b≤6.5, and 0<x≤0.06 respectively;
• wherein the phosphor has a Raman spectrum in which an intensity ratio (I1/I0), which is a ratio of the peak intensity (I1) in a Raman shift of 600±10 cm−1 assigned to Mn—F bonds in the crystal to that (I0) in a Raman shift of 650±10 cm−1 assigned to Si—F bonds in the crystal, is 0.09 to 0.17;
• wherein the phosphor has an absorptivity (α) in a range of 66% to 83.9%;
• and
• wherein the absorptivity (α) is equal to an external quantum efficiency (η) of the phosphor/an internal quantum efficiency (η′) of the phosphor, wherein the internal quantum efficiency (η′) of the phosphor is represented by formula (II) below, and wherein the external quantum efficiency (η) of the phosphor is represented by formula (III) below,
• internal
• ⁢
• ⁢
• quantum
• ⁢
• ⁢
• efficiency
• (
• η
• ′
• )
• =
• ∫
• λ
• ·
• [
• P
• ⁡
• (
• λ
• )
• ]
• ⁢
• d
• ⁢
• ⁢
• λ
• ∫
• λ
• ·
• [
• E
• ⁡
• (
• λ
• )
• -
• R
• ⁡
• (
• λ
• )
• ]
• ⁢
• d
• ⁢
• ⁢
• λ
• (
• II
• )
• external
• ⁢
• ⁢
• quantum
• ⁢
• ⁢
• efficiency
• (
• η
• )
• =
• ∫
• λ
• ·
• [
• P
• ⁡
• (
• λ
• )
• ]
• ⁢
• d
• ⁢
• ⁢
• λ
• ∫
• λ
• ·
• [
• E
• ⁡
• (
• λ
• )
• ]
• ⁢
• d
• ⁢
• ⁢
• λ
• (
• III
• )
• wherein E(λ) represents a whole spectrum of light emitted by an excitation light source onto the phosphor in terms of the number of photons,
• wherein R(λ) represents a spectrum of light emitted by the excitation light source but reflected by the phosphor in terms of the number of photons, and
• wherein P(λ) represents an emission spectrum of the phosphor in terms of the number of photons.