Laravelのコントローラ処理でエラー Target class [コントローラ名] does not exist. が表示される

#やりたいこと
laravelのルーティングでコントローラを指定しHTMLを表示させようと思っています。
期待動作はhttp://127.0.0.1:8000/sampleへのアクセスで以下のように表示することです。

#エラー内容
上記URLへアクセスすると以下のようなエラー表示になります。

laravel
1**Illuminate\Contracts\Container\BindingResolutionException
2Target class [SampleController] does not exist.**
3
4Illuminate\Container\Container::build
5C:\xampp\laravel5.8\vendor\laravel\framework\src\Illuminate\Container\Container.php:811
6
7     *
8
9     * @throws \Illuminate\Contracts\Container\BindingResolutionException
10
11     */
12
13    public function build($concrete)
14
15    {
16
17        // If the concrete type is actually a Closure, we will just execute it and
18
19        // hand back the results of the functions, which allows functions to be
20
21        // used as resolvers for more fine-tuned resolution of these objects.
22
23        if ($concrete instanceof Closure) {
24
25            return $concrete($this, $this->getLastParameterOverride());
26
27        }
28
29 
30
31        try {
32
33            $reflector = new ReflectionClass($concrete);
34
35        } catch (ReflectionException $e) {
36
37            throw new BindingResolutionException("Target class [$concrete] does not exist.", 0, $e);
38
39        }
40
41 
42
43        // If the type is not instantiable, the developer is attempting to resolve
44
45        // an abstract type such as an Interface or Abstract Class and there is
46
47        // no binding registered for the abstractions so we need to bail out.
48
49        if (! $reflector->isInstantiable()) {
50
51            return $this->notInstantiable($concrete);
52
53        }
54
55 
56
57        $this->buildStack[] = $concrete;
58
59 
60
61        $constructor = $reflector->getConstructor();
62
63 
64
65        // If there are no constructors, that means there are no dependencies then
66
67        // we can just resolve the instances of the objects right away, without
68
69

#作成した各ファイル

webphp
1<?php
2
3use Illuminate\Support\Facades\Route;
4
5/*
6|--------------------------------------------------------------------------
7| Web Routes
8|--------------------------------------------------------------------------
9|
10| Here is where you can register web routes for your application. These
11| routes are loaded by the RouteServiceProvider within a group which
12| contains the "web" middleware group. Now create something great!
13|
14*/
15
16
17Route::get('/sample', 'SampleController@index');

SampleControllerphp
1<?php
2
3namespace App\Http\Controllers;
4
5use Illuminate\Http\Request;
6
7class SampleController extends Controller
8{
9    public function index()
10    {
11        return view('sample');
12    }
13}
14