having an n doped ohm contact buffer layer and a manufacturing method therefor in the present invention a highly n doped ohm contact buffer layer with an electronic concentration up to 1 u00d7 10 18 cm 3 is formed on the n side of a light emitting epitaxy layer when a growth substrate is removed the n type ohm contact buffer layer on the surface is exposed which is a no nitride polarity face n type gan base material with a lower energy gap an n type ohm contact electrode is prepared on the n type ohm contact buffer layer and follows the ti al ohm contact electrode which can overcome the problem of the existing vertical gallium nitride based vertical light emitting diode that the voltage of the thin film gan base light emitting device is unreliable because the ohm contact electrode on the nitride face gan base semiconductor layer is easy to crack due to temperature application_number US 201314369930 A description the present disclosure will be described in detail with reference to the accompanying figures and preferred embodiments in specific device design and manufacture the led structures according to the present disclosure will be adjusted in terms of structure and dimension to some extent and changed with regards to the material selection based on specific application fields and process applications fig1 is the schematic diagram of an led epitaxial structure according to embodiment 1 as shown in fig1 an led epitaxial structure is provided including an epitaxial growth substrate 101 an n type ohmic contact buffer layer 102 over the epitaxial growth substrate 101 an n type gan based semiconductor layer 103 over the n type ohmic contact buffer layer 102 an active layer 104 over the n type gan based semiconductor layer 103 and a p type.