Can you identify any literary devices in “The Raven” and explain their purpose and why they are gothic ?

In "The Raven" Poe joins a long line of poets who have used the conceit of bonding with a bird figure as an expression of hope or despair, of desire, and of fear.
The Gothic element is present in the setting, at midnight in "bleak December," and above all in the supernatural appearance of a wild, dark bird that flies into the poet's chamber and speaks to him. Poe's use of trochaic meter, as opposed to the much more frequently employed (in English) iambic meter, creates a sing-song impression, as if a nursery rhyme, ironically, is being recited. But it simultaneously lends a trance-like quality to the entire poem. The speaker is in the midst of a dream about "the lost Lenore," and the raven visits him not to give hope but ultimately to confirm his despair of ever being reunited with her.
Poe's use of repetition reinforces the hypnotic tone of the poem, as in "tapping, / Tapping at my chamber door," and "And this mystery explore,-- / Let my heart be still a moment, / And this mystery explore." The phrase "and nothing more" appears multiple times, as does, most significantly, the raven's repeated "Nevermore!" There are frequent feminine rhymes: rhymes which are multi-syllabic. In English (unlike in Italian and other languages), feminine rhymes often have a slightly humorous effect, and Poe uses this to distance himself, and the reader, from the emotion of the poem and to intensify a quality that is mechanical in a subtly frightening way. The poem unwinds like a watch-spring, having an irresistible and unstoppable power, like that of a nightmare from which the sleeper is unable to break free.
In his essay "The Poetic Principle," Poe makes it clear that he values poetry for its musical quality as well as for its ability to convey emotion. As in "The Bells," in "The Raven" Poe creates a poetic fabric like a melody which, again, establishes an ironic distance between himself and the baffling and uncontrolled hopelessness of the poet's love for Lenore. In "The Bells" we do not fully sense the pathos in which the speaker is enveloped until the line "And the moaning and the groaning of the bells!"; in "The Raven," Poe delays until the final stanza the fact that his soul will "nevermore" be lifted from the shadow of the raven.
In his preface to an anthology of Romantic poetry, W.H. Auden stated that Poe was the first poet in English to create a completely unreal world, one in which the actual world is replaced by a dream. This may be an exaggeration, but we can see some truth in it if we compare "The Raven" with John Keats's "Ode to a Nightingale." Keats sees the bird as a symbol of a world of dreams he wishes to enter, but when he does so, and rhapsodizes, "Tender is the night!" he also concludes that "....here there is no light / Save what from heaven is with the breezes blown, / Through verdurous glooms and winding mossy ways." Keats backs off from joining the realm of illusion to which the bird beckons him. Poe, in "The Raven," has allowed himself to be captured by his bird, and to reside in a world such as he describes in his "The City in the Sea," which is a realm of eternal night.